1. Field of the Invention
The present invention relates generally to the fields of antibodies, angiogenesis and tumor treatment. More particularly, it provides anti-VEGF antibodies that specifically inhibit VEGF binding to only one (VEGFR2) of the two VEGF receptors. Such antibodies inhibit angiogenesis and induce tumor regression, and yet have improved safety due to their specific blocking properties. The antibody-based compositions and methods of the invention also extend to the use of immunoconjugates and other therapeutic combinations, kits and methods, including those with prodrugs.
2. Description of the Related Art
Tumor cell resistance to chemotherapeutic agents represents a significant problem in clinical oncology. In fact, this is one of the main reasons why many of the most prevalent forms of human cancer still resist effective chemotherapeutic intervention, despite certain advances in this field.
Another tumor treatment strategy is the use of an xe2x80x9cimmunotoxinxe2x80x9d, in which an anti-tumor cell antibody is used to deliver a toxin to the tumor cells. However, in common with chemotherapeutic approaches, immunotoxin therapy also suffers from significant drawbacks when applied to solid tumors. For example, antigen-negative or antigen-deficient cells can survive and repopulate the tumor or lead to further metastases.
A further reason for solid tumor resistance to antibody-based therapies is that the tumor mass is generally impermeable to macromolecular agents such as antibodies and immunotoxins (Burrows et al., 1992; Dvorak et al., 1991a; Baxter and Jain, 1991). Both the physical diffusion distances and the interstitial pressure within the tumor are significant limitations to this type of therapy. Therefore, solid tumors, which make up over 90% of all human cancers, have thus far proven resistant to antibody and immunotoxin treatment.
A more recent strategy has been to target the vasculature of solid tumors. Targeting the blood vessels of the tumors, rather than the tumor cells themselves, has certain advantages in that it is not likely to lead to the development of resistant tumor cells, and that the targeted cells are readily accessible. Moreover, destruction of the blood vessels leads to an amplification of the anti-tumor effect, as many tumor cells rely on a single vessel for their oxygen and nutrients (Burrows and Thorpe, 1994a; 1994b). Exemplary vascular targeting strategies are described in U.S. Pat. Nos. 5,855,866 and 5,965,132, which particularly describe the targeted delivery of anti-cellular agents and toxins to markers of tumor vasculature.
Another effective version of the vascular targeting approach is to target a coagulation factor to a marker expressed or adsorbed within the tumor vasculature (Huang et al., 1997; U.S. Pat. Nos. 5,877,289, 6,004,555, and 6,093,399). The delivery of coagulants, rather than toxins, to tumor vasculature has the further advantages of reduced immunogenicity and even lower risk of toxic side effects. As disclosed in U.S. Pat. No. 5,877,289, a preferred coagulation factor for use in such tumor-specific xe2x80x9ccoaguligandsxe2x80x9d is a truncated version of the human coagulation-inducing protein, Tissue Factor (TF), the major initiator of blood coagulation.
Although the specific delivery of toxins and coagulation factors to tumor blood vessels represents a significant advance in tumor treatment, certain peripheral tumor cells can survive the intratumoral destruction caused by such therapies. Anti-angiogenic strategies would therefore be of use in combination with the tumor destruction methods of U.S. Pat. Nos. 5,855,866 and 5,877,289.
Anti-angiogenic tumor treatment strategies are based upon inhibiting the proliferation of budding vessels, generally at the periphery of a solid tumor. These therapies are mostly applied to reduce the risk of micrometastasis or to inhibit further growth of a solid tumor after more conventional intervention (such as surgery or chemotherapy).
Angiogenesis is the development of new vasculature from preexisting blood vessels and/or circulating endothelial stem cells (Asahara et al., 1997; Springer et al., 1998; Folkman and Shing, 1992). Angiogenesis plays a vital role in many physiological processes, such as embryogenesis, wound healing and menstruation. Angiogenesis is also important in certain pathological events. In addition to a role in solid tumor growth and metastasis, other notable conditions with an angiogenic component are arthritis, psoriasis and diabetic retinopathy (Hanahan and Folkman, 1996; Fidler and Ellis, 1994).
Angiogenesis is regulated in normal and malignant tissues by the balance of angiogenic stimuli and angiogenic inhibitors that are produced in the target tissue and at distant sites (Fidler et al., 1998; McNamara et al., 1998). Vascular endothelial growth factor-A (VEGF, also known as vascular permeability factor, VPF) is a primary stimulant of angiogenesis. VEGF is a multifunctional cytokine that is induced by hypoxia and oncogenic mutations and can be produced by a wide variety of tissues (Kerbel et al., 1998; Mazure et al., 1996).
The recognition of VEGF as a primary stimulus of angiogenesis in pathological conditions has led to various attempts to block VEGF activity. Inhibitory anti-VEGF receptor antibodies, soluble receptor constructs, antisense strategies, RNA aptamers against VEGF and low molecular weight VEGF receptor tyrosine kinase (RTK) inhibitors have all been proposed for use in interfering with VEGF signaling (Siemeister et al., 1998). In fact, monoclonal antibodies against VEGF have been shown to inhibit human tumor xenograft growth and ascites formation in mice (Kim et al., 1993; Asano et al., 1998; Mesiano et al., 1998; Luo et al., 1998a; 1998b; Borgstrom et al., 1996; 1998).
Although the foregoing studies underscore the importance of VEGF in solid tumor growth, and its potential as a target for tumor therapy, the identification of additional agents that inhibit VEGF-induced angiogenesis would be of benefit in expanding the number of therapeutic options. The development of therapeutic agents that more specifically inhibit VEGF receptor binding would represent an important advance, so long as their anti-tumor effects were not substantially compromised by the improved specificity.
The present invention overcomes certain drawbacks in the prior art by providing new therapeutic compositions and methods for use in anti-angiogenic and anti-tumor treatment. The invention is based on antibodies that specifically inhibit VEGF binding to only one (VEGFR2) of the two primary VEGF receptors. Such antibodies inhibit angiogenesis and induce tumor regression as effectively as other anti-VEGF antibodies, including those already in clinical trials, and yet have improved safety due to their specific blocking properties. The compositions and methods of the invention also extend to the use of immunoconjugates and combinations, including prodrugs, using the specific category of antibodies provided.
A particular advantage of the present invention is that the antibodies provided inhibit VEGF binding only to VEGFR2, and not VEGFR1. This contrasts with the leading antibodies in the prior art, including A4.6.1, which inhibit VEGF binding to both VEGFR2 and VEGFR1. As VEGFR1 has important biological roles unconnected to angiogenesis, particularly in macrophage migration and chemotaxis, and osteoclast and chondroclast function, the present ability to inhibit only VEGFR2-mediated angiogenesis is a distinct advantage. This translates into notable clinical benefits in that macrophages are still able to mediate host anti-tumor responses and that bone metabolism, e.g., in the treatment of pediatric cancers, is not adversely affected.
A further advantage is that, as binding of VEGF to VEGFR1 is maintained in the presence of the antibodies of the invention, they can be used to specifically deliver attached therapeutic agents to tumor vasculature by virtue of binding to VEGF that is bound to VEGFR1, which is upregulated on tumor endothelium. In the context of immunoconjugates, therefore, the present invention provides agents that have both anti-angiogenic and tumor destructive properties within the same molecule.
Yet a further advantage exists in the ability of the compositions provided to neutralize the survival signal of VEGF, which is mediated through VEGFR2. The naked and conjugated antibodies of the invention thus form synergistic combinations with other therapies and/or attached agents, particularly those methods and agents that fail to achieve maximal effectiveness in vivo due to the ability of VEGF to counteract their destructive properties.
The present invention thus provides antibodies that specifically block VEGF binding to the VEGFR2 receptor, or that block VEGF binding to essentially only the VEGFR2 receptor. Such antibodies significantly inhibit VEGF binding to the VEGFR2 receptor (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGFR1 receptor (Flt-1). The antibodies thus inhibit VEGF binding to the VEGFR2 receptor (KDR/Flk-1), do not substantially inhibit VEGF binding to the VEGFR1 receptor (Flt-1), exhibit anti-angiogenic and anti-tumor effects in vivo and do not significantly inhibit macrophage chemotaxis, osteoclast or chondroclast functions.
The antibodies of the invention are thus succinctly termed xe2x80x9cVEGFR2-blocking, non-VEGFR1-blocking, anti-VEGF antibodiesxe2x80x9d. Even more succinctly, they are termed xe2x80x9cVEGFR2-blocking, anti-VEGF antibodiesxe2x80x9d, which is used for simplicity in reference to all compositions, uses and methods of the invention. A xe2x80x9cVEGFR2-blocking, anti-VEGF antibodyxe2x80x9d is an antibody against VEGF that blocks VEGF binding to the VEGFR2 receptor. It will be clear that such antibodies are not antibodies against the VEGFR2 receptor itself.
Prior to the present invention, there was no motivation to generate anti-VEGF antibodies that specifically block VEGF binding to the VEGFR2 receptor, but not the VEGFR1, neither were any advantages of such antibodies envisioned. Importantly, as blocking antibodies need to physically prevent the interaction of a growth factor and its receptor(s), and as receptor binding sites on growth factors are limited in size, there was nothing to suggest that such specific VEGFR2-blocking, anti-VEGF antibodies could be developed.
However, in light of the inventors"" surprising discoveries disclosed herein, the art is now provided with the knowledge that such specific inhibitory anti-VEGF antibodies can be prepared and have distinct advantages. The present application further describes the methodology for generating candidate VEGFR2-blocking, anti-VEGF antibodies and the routine technical aspects of the assays required to identify actual VEGFR2-blocking specific antibodies from the pool of candidates. In light of this invention, therefore, a range of VEGFR2-blocking, anti-VEGF antibodies can be made and used in a variety of embodiments, including in the inhibition of angiogenesis and the treatment of angiogenic diseases and tumors without inhibiting VEGF signaling via the VEGFR1 receptor and without the notable drawbacks and side effects associated therewith.
As used throughout the entire application, the terms xe2x80x9caxe2x80x9d and xe2x80x9canxe2x80x9d are used in the sense that they mean xe2x80x9cat least onexe2x80x9d, xe2x80x9cat least a firstxe2x80x9d, xe2x80x9cone or morexe2x80x9d or xe2x80x9ca pluralityxe2x80x9d of the referenced components or steps, except in instances wherein an upper limit is thereafter specifically stated. Therefore, an xe2x80x9cantibodyxe2x80x9d, as used herein, means xe2x80x9cat least a first antibodyxe2x80x9d. The operable limits and parameters of combinations, as with the amounts of any single agent, will be known to those of ordinary skill in the art in light of the present disclosure.
Antibodies that xe2x80x9cspecifically inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1)xe2x80x9d can now be identified by competition and/or functional assays. The preferred assays, for simplicity, are competition assays based upon an ELISA. In competition assays, one pre-mixes or admixes VEGF with varying amounts of the test antibodies (e.g., 100-fold to 1000-fold molar excess) and determines the ability of the test antibodies to reduce VEGF binding to VEGFR2. VEGF can be pre-labeled and detected directly, or can be detected using a (secondary) anti-VEGF antibody or a secondary and tertiary antibody detection system. An ELISA format of such a competition assay is a preferred format, but any type of immunocompetition assay may be conducted.
VEGF binding to VEGFR2 in the presence of a completely irrelevant antibody (including non-blocking anti-VEGF monoclonal antibodies) is the control high value (100%) in such a competition assay. In a test assay, a significant reduction in VEGF binding to VEGFR2 in the presence of a test antibody is indicative of a test antibody that significantly inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1).
A significant reduction is a xe2x80x9creproduciblexe2x80x9d, i.e., consistently observed, reduction in binding. A xe2x80x9csignificant reductionxe2x80x9d in terms of the present application is defined as a reproducible reduction (in VEGF binding to VEGFR2) of at least about 45%, about 50%, about 55%, about 60% or about 65% at any amount between about 100 fold and about 1000 fold molar excess of antibody over VEGF.
As a preferred feature of the invention is that the antibodies provided do not substantially inhibit VEGF binding to VEGFR1, antibodies that exhibit a moderately significant reduction of VEGF binding to VEGFR2 will still be useful, so long as they do not substantially inhibit VEGF binding to VEGFR1. Nonetheless, more preferred antibodies will be those that have a more significant ability to inhibit VEGF binding to VEGFR2. These antibodies are those that exhibit a reproducible ability to reduce VEGF binding to VEGFR2 by at least about 70%, about 75% or about 80% at any amount between about 100 fold and about 1000 fold molar excess of antibody over VEGF. Although not required to practice the invention, antibodies that reduce VEGF binding to VEGFR2 by at least about 85%, about 90%, about 95% or even higher are by no means excluded.
Anti-VEGF antibodies, or antigen-binding fragments thereof, that inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1) are readily confirmed by simple competition assays such as those described above, but using VEGFR1.
Absence of a significant reduction is a xe2x80x9creproduciblexe2x80x9d, i.e., consistently observed, xe2x80x9csubstantial maintenance of bindingxe2x80x9d. A xe2x80x9csubstantial maintenance of bindingxe2x80x9d in terms of the present application is defined as a reproducible maintenance (in VEGF binding to VEGFR1) of at least about 60%, about 75%, about 80% or about 85% at any amount between about 100 fold and about 1000 fold molar excess of antibody over VEGF.
The intention of using antibodies that do not substantially inhibit VEGF binding to VEGFR1 is to maintain the biological functions mediated by VEGFR1. Therefore, an antibody need only maintain sufficient VEGF binding to VEGFR1 so that a biological response is induced by VEGF. Nonetheless, more preferred antibodies will be those that have a more significant ability to maintain VEGF binding to VEGFR1. These antibodies are those that exhibit a reproducible ability to maintain VEGF binding to VEGFR1 at levels of at least about 88%, about 90%, about 92%, about 95% or of about 98-99% at any amount between about 100 fold and about 1000 fold molar excess of antibody over VEGF.
It will be understood that antibodies that more substantially inhibit VEGF binding to VEGFR2 can likely tolerate more reduction in binding VEGFR1. Equally, where an antibody has a moderate reduction in VEGF binding to VEGFR2, the maintenance of binding to VEGFR1 should be more stringently pursued.
Another preferred binding assay to identify and/or confirm that an antibody inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) is a co-precipitation assay. A co-precipitation assay tests the ability of an antibody to block the binding of VEGF to one or more receptors in solution. In such an assay, VEGF or detectably-labeled VEGF is incubated with a suitable form of the receptor.
There are many formats for conducting immunoprecipitation or co-precipitation assays. In the present case, a xe2x80x9csuitable form of the receptorxe2x80x9d may be the VEGFR2 receptor at issue or the extracellular domain of the receptor. Immunoprecipitation with then require, as well as the standard reagents, the presence of an antibody against the VEGFR2 receptor or an epitope on the extracellular domain of the receptor distinct from the site to which VEGF binds. The present invention provides other xe2x80x9csuitablexe2x80x9d forms of the VEGF receptors, namely the extracellular domains of the receptors linked to an Fc antibody portion. Such receptor/Fc constructs can be precipitated by incubation with an effective immunoprecipitating composition, such as a Protein A-based composition.
Irrespective of the suitable receptor, the immunoprecipitation or co-precipitation assays are preferably conducted with controls. The ability of VEGF alone to bind to the chosen receptor should be confirmed by precipitation in the absence of an anti-VEGF antibody. Preferably, parallel incubations are conducted in the presence or absence of an antibody with known binding properties to act as a control. Most preferably, assays using both a blocking control and non-blocking control antibody are run in parallel.
Any bound immunological species are then immunoprecipitated, e.g., by incubation with an effective immunoprecipitating composition, such as a Protein A composition or Protein A sepharose beads. The precipitate is then tested for the presence of VEGF. Where the VEGF in the initial incubation was detectably-labeled VEGF, such as radio-labeled VEGF, any VEGF in the immunoprecipitates can be detected directly. Any non-labeled VEGF in the immunoprecipitates may be detected by other suitable means, e.g., by gel separation and immunodetection with an anti-VEGF antibody.
The ability of an antibody to block VEGF binding to a VEGF receptor, such as VEGFR2, in such a co-precipitation assay can be readily quantitated, although qualitative results are also valuable. Quantification can be achieved by direct measurement of labeled VEGF or e.g., by densitometric analyses of immunodetected VEGF. Antibodies that exhibit a reproducible, i.e., consistently observed, ability to inhibit VEGF binding to VEGFR2 can thus be detected, and useful antibodies can be chosen according to the quantitative criteria outlined above.
Anti-VEGF antibodies that do not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1) can also be readily identified by conducting co-precipitation assays as described above, but using VEGFR1 rather than VEGFR2. Therefore, anti-VEGF antibodies that inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1) can also be readily identified using such methods.
The present application also provides various functional assays to identify and/or confirm that an antibody significantly inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1). These are generally related to the identification of VEGFR2 as the receptor responsible for certain defined biological responses. Although less preferred than the foregoing competition-type assays, which are conducted in cell-free systems and are most reproducible, reliable, labor-saving and cost-effective, the following assays are nonetheless useful in the context of the present invention.
For example, a VEGFR2-blocking, anti-VEGF antibody may be identified by testing for the ability to inhibit VEGF-mediated endothelial cell growth (inhibiting the mitogenic activity of VEGF). Any suitable assay may be employed using any of a variety of endothelial cells in the presence of VEGF with or without test antibodies. Preferably, duplicate assays are run in parallel, such as those without VEGF and those with control antibodies of defined properties (both blocking and non-blocking). Endothelial cell growth may be determined and preferably accurately quantified by any acceptable means of determining cell number, including colorimetric assays.
An antibody with an ability to inhibit VEGF-mediated endothelial cell growth will generally exhibit a consistently observed inhibition of VEGF-mediated endothelial cell growth of about 25%, 30%, 35%, 40% 45% or 50% or so. Inhibition in such ranges will indicate an antibody with properties sufficient to inhibit angiogenesis in vivo. Antibodies with more significant inhibitory activity are not excluded from the invention.
Further functional assays to identify antibodies in accordance with the present invention are assays to test blocking of VEGF-induced phosphorylation. Any suitable assay may be employed using any of a variety of endothelial cells that express any form of native or recombinant phosphorylatable VEGFR2. Cells are incubated with VEGF in the presence or absence of the antibody to be tested for a suitable time period. Preferably, duplicate assays are run in parallel, such as those without VEGF and those with control antibodies of defined properties (both blocking and non-blocking).
VEGF-induced phosphorylation of VEGFR2 may be determined and preferably accurately quantified by any acceptable means. Generally, VEGFR2 is immunoprecipitated for further analyses. The degree of phosphorylation of VEGFR2 may be determined directly, for example, the cells may have been incubated with 32P-labelled ATP, allowing direct quantification of the 32P within the immunoprecipitated VEGFR2. Preferably, the immunoprecipitated VEGFR2 are analyzed by other means, e.g., by gel separation and immunodetection with an antibody that binds to phosphotyrosine residues. An antibody with an ability to inhibit VEGF-induced phosphorylation of VEGFR2 will generally exhibit a consistently observed reduction in the levels of phosphorylated VEGFR2.
Yet further functional assays to identify VEGFR2-blocking, anti-VEGF antibodies in accordance with the present invention are assays to test inhibition of VEGF-induced vascular permeability. Although any such assay may be used, a particularly suitable assay is the Miles permeability assay, wherein animals such as guinea pigs are injected with a dye, such as Evan""s blue dye, and the appearance of the dye in the animal skin is determined after the provision of VEGF in the presence or absence of test antibodies. Preferably, duplicate studies are conducted in parallel, such as those without VEGF and those with control antibodies of defined properties (both blocking and non-blocking). The appearance of dye in the animal skin is typically as spots, such as blue spots, in the back of the animal, which can be photographed and measured.
VEGFR2-blocking, anti-VEGF antibodies will inhibit VEGF-induced-vascular permeability as a consistently observed inhibition at low concentrations, such as when provided at a 100-fold, or 1000-fold molar excess over VEGF. Antibodies that do not block VEGF binding to VEGFR2 will not show any significant inhibition of VEGF induced-vascular permeability. Generally, antibodies that block VEGF-induced permeability only at high concentrations, such as at a 10-fold molar excess over VEGF, will not be antibodies with properties in accordance with the present invention.
Widely accepted functional assays of angiogenesis and, hence, anti-angiogenic agents are the corneal micropocket assay of neovascularization and the chick chorio-allantoic membrane assay (CAM) assay. U.S. Pat. No. 5,712,291 is specifically incorporated herein by reference to show that the corneal micropocket and CAM assays are sufficiently predictive to identify agents for use in the treatment of an extremely wide range of angiogenic diseases.
U.S. Pat. No. 5,001,116 is also specifically incorporated herein by reference for purposes of describing the CAM assay. Essentially, fertilized chick embryos are removed from their shell on day 3 or 4, and a methylcellulose disc containing the test compound is implanted on the chorioallantoic membrane. The embryos are examined approximately 48 hours later and, if a clear avascular zone appears around the methylcellulose disc, the diameter of that zone is measured. As disclosed in U.S. Pat. No. 5,712,291, specifically incorporated herein by reference for this purpose, in the context of the present invention, the appearance of any avascular zone is sufficient to evidence an anti-angiogenic antibody. The larger the zone, the more effective the antibody.
The corneal micropocket assay of neovascularization may be practiced using rat or rabbit corneas. This in vivo model is widely accepted as being predictive of clinical usefulness, as evidenced by U.S. Pat. Nos. 5,712,291 and 5,871,723, each specifically incorporated herein by reference for evidence purposes. Although not believed to be particularly relevant the present invention, the corneal assays are preferable over the CAM assay because they will generally recognize compounds that are inactive per se but are metabolized to yield active compounds.
In the present invention, the corneal micropocket assay is used to identify an anti-angiogenic agent. This is evidenced by a significant reduction in angiogenesis, as represented by a consistently observed and preferably marked reduction in the number of blood vessels within the cornea. Such responses are preferably defined as those corneas showing only an occasional sprout and/or hairpin loop that displayed no evidence of sustained growth when contacted with the test substance.
Exemplary VEGFR2-blocking, anti-VEGF antibodies (and antigen-binding fragments) of the invention include those that:
(a) significantly inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1);
(b) do not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1);
(c) inhibit, and preferably, significantly inhibit, VEGF-induced phosphorylation of VEGFR2;
(d) inhibit, and preferably, significantly inhibit, VEGF-induced vascular permeability;
(e) inhibit, and preferably, significantly inhibit, VEGF-mediated endothelial cell proliferation;
(f) inhibit, and preferably, significantly inhibit, angiogenesis;
(g) do not significantly inhibit VEGFR1-mediated stimulation or activation of macrophages, osteoclasts or chondroclasts; and
(h) localize to tumor vasculature and tumor stroma upon administration to an animal with a vascularized tumor.
A particular aspect of the invention is based on the inventors"" original, surprising discovery of antibodies that specifically inhibited VEGF binding to the VEGFR2 receptor, that had significant anti-tumor effects in vivo and that did not inhibit VEGF binding to the VEGFR1 receptor. In certain embodiments, the present invention thus provides antibodies of defined epitope-specificity, wherein such antibodies, or antigen-binding fragments thereof, bind to essentially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
The invention as claimed is enabled in accordance with the present specification and readily available technological references, know-how and starting materials. Nonetheless, a sample of the hybridoma cell line producing the 2C3 monoclonal antibody was submitted Mar. 27, for receipt Mar. 28, 2000, for deposit with the American Type Culture Collection (ATCC), 10801 University Blvd., Manassas, Va. 20110-2209, U.S.A. and given ATCC Accession number ATCC PTA 1595 on Apr. 11, 2000. This deposit was made under the provisions of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure and the regulations thereof (Budapest Treaty). The hybridoma will be made available by the ATCC under the terms of the Budapest Treaty upon issue of a U.S. patent with pertinent claims. Availability of the deposited hybridoma is not to be construed as a license to practice the invention in contravention of the rights granted under the authority of any government in accordance with its patent laws.
Certain preferred compositions are therefore compositions comprising at least a first anti-VEGF antibody, or antigen-binding fragment thereof, or at least a first purified anti-VEGF antibody, or antigen-binding fragment thereof, that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595); compositions comprising at least a first monoclonal antibody, or antigen-binding fragment thereof, that binds to VEGF at essentially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595); and compositions comprising at least a first anti-VEGF monoclonal antibody, or antigen-binding fragment thereof, that binds to the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
Notwithstanding, certain other compositions, antibodies, methods, and particularly first and second medical uses of the invention, concern anti-VEGF antibodies, or antigen-binding fragments thereof, that bind to the same, or substantially the same, epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) other than the monoclonal antibody 2C3 (ATCC PTA 1595) itself.
The terms xe2x80x9cthat bind to about, substantially or essentially the same, or the same, epitope asxe2x80x9d the monoclonal antibody 2C3 (ATCC PTA 1595) mean that an antibody xe2x80x9ccross-reactsxe2x80x9d with the monoclonal antibody 2C3 (ATCC PTA 1595). xe2x80x9cCross-reactive antibodiesxe2x80x9d are those that recognize, bind to or have immunospecificity for substantially or essentially the same, or the same, epitope or xe2x80x9cepitopic sitexe2x80x9d as the monoclonal antibody 2C3 (ATCC PTA 1595) such that are able to effectively compete with the monoclonal antibody 2C3 (ATCC PTA 1595) for binding to VEGF. xe2x80x9c2C3-cross-reactive antibodiesxe2x80x9d are succinctly termed xe2x80x9c2C3-like antibodiesxe2x80x9d and xe2x80x9c2C3-based antibodiesxe2x80x9d, and such terms are used interchangeably herein and apply to compositions, uses and methods.
The identification of one or more antibodies that bind(s) to about, substantially, essentially or at the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) is a straightforward technical matter now that 2C3, with its advantageous properties, has been provided. As the identification of cross-reactive antibodies is determined in comparison to a reference antibody, it will be understood that actually determining the epitope to which the reference antibody (2C3) and the test antibody bind is not in any way required in order to identify an antibody that binds to the same or substantially the same epitope as the monoclonal antibody 2C3. However, considerable information on the epitope bound by 2C3 is included herein and epitope mapping can be further performed, as described by Champe et al. (1995, specifically incorporated herein by reference).
The identification of cross-reactive antibodies can be readily determined using any one of variety of immunological screening assays in which antibody competition can be assessed. All such assays are routine in the art and are further described herein in detail. U.S. Pat. No. 5,660,827, issued Aug. 26, 1997, is specifically incorporated herein by reference for purposes including even further supplementing the present teaching concerning how to make antibodies that bind to the same or substantially the same epitope as a given antibody, such as 2C3.
For example, where the test antibodies to be examined are obtained from different source animals, or are even of a different isotype, a simple competition assay may be employed in which the control (2C3) and test antibodies are admixed (or pre-adsorbed) and applied to a VEGF antigen composition. By xe2x80x9cVEGF antigen compositionxe2x80x9d is meant any composition that contains a 2C3-binding VEGF antigen as described herein, such as free VEGF. Thus, protocols based upon ELISAs and Western blotting are suitable for use in such simple competition studies.
In certain embodiments, one would or pre-mix the control antibodies (2C3) with varying amounts of the test antibodies (e.g., 1:10 or 1:100) for a period of time prior to applying to an antigen composition. In other embodiments, the control and varying amounts of test antibodies can simply be admixed during exposure to the antigen composition. In any event, by using species or isotype secondary antibodies one will be able to detect only the bound control antibodies, the binding of which will be reduced by the presence of a test antibody that recognizes substantially the same epitope.
In conducting an antibody competition study between a control antibody and any test antibody (irrespective of species or isotype), one may first label the control (2C3) with a detectable label, such as, e.g., biotin or an enzymatic (or even radioactive) label to enable subsequent identification. In these cases, one would pre-mix or incubate the labeled control antibodies with the test antibodies to be examined at various ratios (e.g., 1:10 or 1:100) and (optionally after a suitable period of time) then assay the reactivity of the labeled control antibodies and compare this with a control value in which no potentially competing test antibody was included in the incubation.
The assay may again be any one of a range of immunological assays based upon antibody hybridization, and the control antibodies would be detected by means of detecting their label, e.g., using streptavidin in the case of biotinylated antibodies or by using a chromogenic substrate in connection with an enzymatic label (such as 3,3xe2x80x25,5xe2x80x2-tetramethylbenzidine (TMB) substrate with peroxidase enzyme) or by simply detecting a radioactive label. An antibody that binds to the same epitope as the control antibodies will be able to effectively compete for binding and thus will significantly reduce control antibody binding, as evidenced by a reduction in bound label.
The reactivity of the (labeled) control antibodies in the absence of a completely irrelevant antibody would be the control high value. The control low value would be obtained by incubating the labeled (2C3) antibodies with unlabelled antibodies of exactly the same type (2C3), when competition would occur and reduce binding of the labeled antibodies. In a test assay, a significant reduction in labeled antibody reactivity in the presence of a test antibody is indicative of a test antibody that recognizes the same epitope, i.e., one that xe2x80x9ccross-reactsxe2x80x9d with the labeled (2C3) antibody.
A significant reduction is a xe2x80x9creproduciblexe2x80x9d, i.e., consistently observed, reduction in binding. A xe2x80x9csignificant reductionxe2x80x9d in terms of the present application is defined as a reproducible reduction (in 2C3 binding to VEGF in an ELISA) of at least about 70%, about 75% or about 80% at any ratio between about 1:10 and about 1:100. Antibodies with even more stringent cross-blocking activities will exhibit a reproducible reduction (in 2C3 binding to VEGF in an ELISA or other suitable assay) of at least about 82%, about 85%, about 88%, about 90%, about 92% or about 95% or so at any ratio between about 1:10 and about 1:100. Complete or near-complete cross-blocking, such as exhibiting a reproducible reduction in 2C3 binding to VEGF of about 99%, about 98%, about 97% or about 96% or so, although by no means required to practice the invention, is certainly not excluded.
The invention is exemplified by monoclonal antibody 2C3, produced by hybridoma ATCC PTA 1595, or an antigen-binding fragment of such a monoclonal antibody. A hybridoma that produces a monoclonal anti-VEGF antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) is another aspect of the invention.
The invention further provides anti-VEGF antibodies that bind to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), prepared by a process comprising immunizing an animal with at least a first immunogenic VEGF component and selecting from the immunized animal an antibody that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595); and anti-VEGF antibodies that bind to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), prepared by a process comprising immunizing an animal with at least a first immunogenic VEGF component and selecting a cross-reactive anti-VEGF antibody from the immunized animal by identifying an antibody that substantially reduces the binding of the 2C3 antibody to VEGF.
Anti-VEGF antibodies, or antigen-binding fragments thereof, that bind to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) and that specifically inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1); and anti-VEGF antibodies, or antigen-binding fragments thereof, that bind to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) and that inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1) form other aspects of the invention.
Antibodies with such combinations of properties can be readily identified by one or more or a combination of the receptor competition, ELISA, co-precipitation, and/or functional assays and the 2C3-crossreactivity assays described above. The guidance concerning the quantitative assessment of 2C3-like antibodies that consistently significantly reduce VEGF binding to VEGFR2 and that consistently do not significantly inhibit VEGF binding to VEGFR1 is as described above.
2C3 is herein shown reduce the amount VEGF that bound to VEGFR2-coated ELISA wells to about 26% and 19%, respectively, at 100 fold and 1000 fold molar excesses over VEGF. These figures equate to reductions in VEGF binding to VEGFR2 of about 74% and about 81%, respectively. 2C3 is herein shown maintain the amount VEGF that bound to VEGFR2-coated ELISA wells at about 92% and 105%, respectively, at 100 fold and 1000 fold molar excesses over VEGF.
It will again be understood that 2C3-like or crossreactive antibodies that more substantially inhibit VEGF binding to VEGFR2 can likely tolerate more reduction in binding VEGFR1. Equally, where an antibody has a moderate reduction in VEGF binding to VEGFR2, the maintenance of binding to VEGFR1 should be more stringently pursued.
Additional exemplary anti-VEGF antibodies (and antigen-binding fragments) of the invention are therefore those that:
(a) bind to a non-conformationally dependent VEGF epitope, as assessed by binding to VEGF in a Western blot;
(b) bind to free VEGF;
(c) significantly inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1);
(d) do not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1);
(e) inhibit, and preferably, significantly inhibit, VEGF-induced phosphorylation of VEGFR2;
(f) inhibit, and preferably, significantly inhibit, VEGF-induced vascular permeability;
(g) inhibit, and preferably, significantly inhibit, VEGF-mediated endothelial cell proliferation;
(h) inhibit, and preferably, significantly inhibit, angiogenesis;
(i) do not significantly inhibit VEGFR1-mediated stimulation or activation of macrophages, osteoclasts or chondroclasts;
(j) localize to tumor vasculature and tumor stroma upon administration to an animal with a vascularized tumor; and
(k) bind to the same or substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
In the following descriptions of the compositions, immunoconjugates, pharmaceuticals, combinations, cocktails, kits, first and second medical uses and all methods in accordance with this invention, the terms xe2x80x9cantibodyxe2x80x9d and xe2x80x9cimmunoconjugatexe2x80x9d, or an antigen-binding region thereof, unless otherwise specifically stated or made clear from the scientific terminology, refer to a range of VEGFR2-blocking, anti-VEGF antibodies as well as to specific 2C3-cross-reactive antibodies.
The terms xe2x80x9cantibodyxe2x80x9d and xe2x80x9cimmunoglobulinxe2x80x9d, as used herein, refer broadly to any immunological binding agent, including polyclonal and monoclonal antibodies. Depending on the type of constant domain in the heavy chains, antibodies are assigned to one of five major classes: IgA, IgD, IgE, IgG, and IgM. Several of these are further divided into subclasses or isotypes, such as IgG1, IgG2, IgG3, IgG4, and the like. The heavy-chain constant domains that correspond to the difference classes of immunoglobulins are termed xcex1, xcex4, xcex5, xcex3 and xcexc, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.
Generally, where antibodies rather than antigen binding regions are used in the invention, IgG and/or IgM are preferred because they are the most common antibodies in the physiological situation and because they are most easily made in a laboratory setting.
The xe2x80x9clight chainsxe2x80x9d of mammalian antibodies are assigned to one of two clearly distinct types: kappa (xcexa) and lambda (xcex), based on the amino acid sequences of their constant domains. There is essentially no preference to the use of xcexa or xcex light chains in the antibodies of the present invention.
The use of monoclonal antibodies (MAbs) or derivatives thereof is much preferred. MAbs are recognized to have certain advantages, e.g., reproducibility and large-scale production, that makes them suitable for clinical treatment. The invention thus provides monoclonal antibodies of the murine, human, monkey, rat, hamster, rabbit and even frog or chicken origin. Murine, human or humanized monoclonal antibodies will generally be preferred.
As will be understood by those in the art, the immunological binding reagents encompassed by the term xe2x80x9cantibodyxe2x80x9d extend to all antibodies from all species, and antigen binding fragments thereof, including dimeric, trimeric and multimeric antibodies; bispecific antibodies; chimeric antibodies; human and humanized antibodies; recombinant and engineered antibodies, and fragments thereof.
The term xe2x80x9cantibodyxe2x80x9d is thus used to refer to any antibody-like molecule that has an antigen binding region, and this term includes antibody fragments such as Fabxe2x80x2, Fab, F(abxe2x80x2)2, single domain antibodies (DABs), Fv, scFv (single chain Fv), linear antibodies, diabodies, and the like. The techniques for preparing and using various antibody-based constructs and fragments are well known in the art (see Kabat et al., 1991, specifically incorporated herein by reference). Diabodies, in particular, are further described in EP 404, 097 and WO 93/11161, each specifically incorporated herein by reference; whereas linear antibodies are further described in Zapata et al. (1995), specifically incorporated herein by reference.
In certain embodiments, the compositions of the invention comprise at least a first anti-VEGF antibody that comprises at least a first variable region that includes an amino acid sequence region of at least about 75%, more preferably, at least about 80%, more preferably, at least about 85%, more preferably, at least about 90% and most preferably, at least about 95% or so amino acid sequence identity to the amino acid sequence of SEQ ID NO:7 or SEQ ID NO:9; wherein said anti-VEGF antibody at least substantially maintains the biological properties of the VEGFR2-blocking, anti-VEGF antibodies of the present invention, as exemplified by the 2C3 antibody.
Identity or homology with respect to these and other anti-VEGF antibody sequences of the present invention is defined herein as the percentage of amino acid residues in a candidate sequence that are identical to the sequences of SEQ ID NO:7 or SEQ ID NO:9, or to the sequence of another anti-VEGF antibody of the invention, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. The maintenance of substantially the same, or even more effective biological properties of the VEGFR2-blocking, anti-VEGF antibody used for the sequence comparison is particularly important. Such comparisons are easily conducted, e.g. using one or more of the various assays described in detail herein.
In certain preferred embodiments, anti-VEGF antibodies of the invention comprise at least a first variable region that includes an amino acid sequence region having the amino acid sequence of SEQ ID NO:7 or SEQ ID NO:9, as exemplified by variable regions that include an amino acid sequence region encoded by the nucleic acid sequences of SEQ ID NO:6 or SEQ ID NO:8. Such sequences are the sequences of Vh and Vxcexa of the 2C3 ScFv encompassing CDR1-3 (complementarity determining regions) of the variable regions of the heavy and light chains.
In other preferred embodiments, second generation antibodies are provided that have enhanced or superior properties in comparison to an original VEGFR2-blocking, anti-VEGF antibody, such as 2C3. For example, the second generation antibodies may have a stronger binding affinity, more effective blocking of VEGF binding to VEGFR2, more specific blocking of VEGF binding to VEGFR2, even less blocking of VEGF binding to VEGFR1, enhanced ability to inhibit VEGF-induced proliferation and/or migration of endothelial cells, superior ability to inhibit, VEGF-induced vascular permeability, and preferably, an increased ability to inhibit VEGF-induced angiogenesis in vivo, and to treat angiogenic diseases, including vascularized tumors.
Comparisons to identify effective second generation antibodies are readily conducted and quantified, e.g., using one or more of the various assays described in detail herein. Second generation antibodies that have an enhanced biological property or activity of at least about b 10-fold, preferably, at least about 20-fold, and more preferably, at least about 50-fold, in comparison to the VEGFR2-blocking, anti-VEGF antibodies of the present invention, as exemplified by the 2C3 antibody, are encompassed by the present invention.
In certain embodiments, the antibodies employed will be xe2x80x9chumanizedxe2x80x9d, part-human or human antibodies. xe2x80x9cHumanizedxe2x80x9d antibodies are generally chimeric monoclonal antibodies from mouse, rat, or other non-human species, bearing human constant and/or variable region domains (xe2x80x9cpart-human chimeric antibodiesxe2x80x9d). Various humanized monoclonal antibodies for use in the present invention will be chimeric antibodies wherein at least a first antigen binding region, or complementarity determining region (CDR), of a mouse, rat or other non-human monoclonal antibody is operatively attached to, or xe2x80x9cgraftedxe2x80x9d onto, a human antibody constant region or xe2x80x9cframeworkxe2x80x9d.
xe2x80x9cHumanizedxe2x80x9d monoclonal antibodies for use herein may also be monoclonal antibodies from non-human species wherein one or more selected amino acids have been exchanged for amino acids more commonly observed in human antibodies. This can be readily achieved through the use of routine recombinant technology, particularly site-specific mutagenesis.
Entirely human, rather than xe2x80x9chumanizedxe2x80x9d, antibodies may also be prepared and used in the present invention. Such human antibodies may be obtained from healthy subjects by simply obtaining a population of mixed peripheral blood lymphocytes from a human subject, including antigen-presenting and antibody-producing cells, and stimulating the cell population in vitro by admixing with an immunogenically effective amount of a VEGF sample. The human anti-VEGF antibody-producing cells, once obtained, are used in hybridoma and/or recombinant antibody production.
Further techniques for human monoclonal antibody production include immunizing a transgenic animal, preferably a transgenic mouse, which comprises a human antibody library with an immunogenically effective amount of a VEGF sample. This also generates human anti-VEGF antibody-producing cells for further manipulation in hybridoma and/or recombinant antibody production, with the advantage that spleen cells, rather than peripheral blood cells, can be readily obtained from the transgenic animal or mouse.
VEGFR2-blocking, anti-VEGF antibodies in accordance with the invention may be readily prepared by processes and methods that comprise:
(a) preparing candidate antibody-producing cells; and
(b) selecting from the candidate antibody-producing cells an antibody that significantly inhibits VEGF binding to VEGFR2 (KDR/Flk-1) and does not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1).
Other antibodies in accordance with the invention may be readily prepared by selecting an antibody that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595). Suitable preparative processes and methods comprise:
(a) preparing candidate antibody-producing cells; and
(b) selecting from the candidate antibody-producing cells an antibody that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595).
One processes of preparing suitable antibody-producing cells and obtaining antibodies therefrom may be conduced in situ in a given patient. That is, simply providing an immunogenically effective amount of an immunogenic VEGF sample to a patient will result in appropriate antibody generation. Thus, the antibody is still xe2x80x9cobtainedxe2x80x9d from the antibody-producing cell, but it does not have to be isolated away from a host and subsequently provided to a patient, being able to spontaneously localize to the tumor vasculature and exert its biological anti-tumor effects. However, such embodiments are not preferred due to the marked lack of specificity.
Suitable antibody-producing cells may also be obtained, and antibodies subsequently isolated and/or purified, by stimulating peripheral blood lymphocytes with VEGF in vitro.
Other methods comprise administering to an animal an immunizing composition comprising at least a first immunogenic VEGF component and selecting from the immunized animal an antibody that significantly inhibits VEGF binding to VEGFR2 (KDR/Flk-1) and does not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1), and optionally that substantially cross-reacts with the monoclonal antibody2C3 (ATCC PTA 1595). These methods generally comprise:
(a) immunizing an animal by administering to the animal at least one dose, and optionally more than one dose, of an immunogenically effective amount of an immunogenic VEGF sample (such as a first human VEGF component, a substantially full length VEGF component, or recombinant human VEGF); and
(b) obtaining a suitable antibody-producing cell from the immunized animal, such as an antibody-producing cell that produces an antibody that significantly inhibits VEGF binding to VEGFR2 (KDR/Flk-1) and does not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1), and optionally that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595).
The immunogenically effective amount of the VEGF sample or samples may be administered as VEGF conjugates, or in combination with any suitable adjuvant, such as Freund""s complete adjuvant. Any empirical technique or variation may be employed to increase immunogenicity. Intact, substantially full length human VEGF is generally preferred as an immunogen.
Irrespective of the nature of the immunization process, or the type of immunized animal, suitable antibody-producing cells are obtained from the immunized animal and, preferably, further manipulated by the hand of man. xe2x80x9cAn immunized animalxe2x80x9d, as used herein, is a non-human animal, unless otherwise expressly stated. Although any antibody-producing cell may be used, most preferably, spleen cells are obtained as the source of the antibody-producing cells. The antibody-producing cells may be used in a preparative process that comprises:
(a) fusing a suitable anti-VEGF antibody-producing cell with an immortal cell to prepare a hybridoma that produces a monoclonal antibody in accordance with the present invention; and
(b) obtaining a suitable anti-VEGF antibody in accordance with the invention from the hybridoma.
xe2x80x9cSuitablexe2x80x9d anti-VEGF antibody-producing cells, hybridomas and antibodies are those that produce, or exist as, VEGFR2-blocking, anti-VEGF antibodies, i.e., antibodies that significantly inhibit VEGF binding to VEGFR2 (KDR/Flk-1) and do not significantly inhibit VEGF binding to the VEGF receptor VEGFR1 (Flt-1), and optionally, that substantially cross-react with the monoclonal antibody 2C3 (ATCC PTA 1595).
Hybridoma-based monoclonal antibody preparative methods thus include those that comprise:
(a) immunizing an animal by administering to the animal at least one dose, and optionally more than one dose, of an immunogenically effective amount of an immunogenic VEGF sample, preferably an intact human VEGF sample;
(b) preparing a collection of monoclonal antibody-producing hybridomas from the immunized animal;
(c) selecting from the collection at least a first hybridoma that produces at least a first VEGFR2-blocking, anti-VEGF monoclonal antibody in accordance with the invention, optionally an anti-VEGF antibody that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595); and
(d) culturing the at least a first antibody-producing hybridoma to provide the at least a first VEGFR2-blocking, anti-VEGF monoclonal antibody; and preferably
(e) obtaining the at least a first VEGFR2-blocking, anti-VEGF monoclonal antibody from the cultured at least a first hybridoma.
In identifying an anti-VEGF antibody that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595), the selecting step may comprise:
(a) contacting a VEGF sample with effective amounts of the monoclonal antibody 2C3 (ATCC PTA 1595) and a candidate antibody; and
(b) determining the ability of the candidate antibody to substantially reduce the binding of the 2C3 antibody to the VEGF sample; wherein the ability of a candidate antibody to substantially reduce the binding of the 2C3 antibody to the VEGF sample is indicative of an anti-VEGF antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
The selecting step may further comprise:
(a) contacting a first VEGF sample with an effective binding amount of the monoclonal antibody 2C3 (ATCC PTA 1595) and determining the amount of 2C3 that binds to VEGF;
(b) contacting a second VEGF sample with an effective binding amount of the monoclonal antibody 2C3 (ATCC PTA 1595) in combination with an effective competing amount of a candidate antibody and determining the amount of 2C3 that binds to VEGF in the presence of the candidate antibody; and
(c) identifying an anti-VEGF antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) by selecting a candidate antibody that reduces the amount of 2C3 that binds to VEGF by, preferably, at least about 80%.
As non-human animals are used for immunization, the monoclonal antibodies obtained from such a hybridoma will often have a non-human make up. Such antibodies may be optionally subjected to a humanization process, grafting or mutation, as known to those of skill in the art and further disclosed herein. Alternatively, transgenic animals, such as mice, may be used that comprise a human antibody gene library. Immunization of such animals will therefore directly result in the generation of suitable human antibodies.
After the production of a suitable antibody-producing cell, most preferably a hybridoma, whether producing human or non-human antibodies, the monoclonal antibody-encoding nucleic acids may be cloned to prepare a xe2x80x9crecombinantxe2x80x9d monoclonal antibody. Any recombinant cloning technique may be utilized, including the use of PCR(trademark) to prime the synthesis of the antibody-encoding nucleic acid sequences. Therefore, yet further appropriate monoclonal antibody preparative methods include those that comprise using the antibody-producing cells as follows:
(a) obtaining at least a first suitable anti-VEGF antibody-encoding nucleic acid molecule or segment from a suitable anti-VEGF antibody-producing cell, preferably a hybridoma; and
(b) expressing the nucleic acid molecule or segment in a recombinant host cell to obtain a recombinant VEGFR2-blocking, anti-VEGF monoclonal antibody in accordance with the present invention.
However, other powerful recombinant techniques are available that are ideally suited to the preparation of recombinant monoclonal antibodies. Such recombinant techniques include the phagemid library-based monoclonal antibody preparative methods comprising:
(a) immunizing an animal by administering to the animal at least one dose, and optionally more than one dose, of an immunogenically effective amount of an immunogenic VEGF sample (such as an intact human VEGF sample);
(b) preparing a combinatorial immunoglobulin phagemid library expressing RNA isolated from the antibody-producing cells, preferably from the spleen, of the immunized animal;
(c) selecting from the phagemid library at least a first clone that expresses at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that substantially cross-reacts with the monoclonal antibody 2C3 (ATCC PTA 1595);
(d) obtaining VEGFR2-blocking, anti-VEGF antibody-encoding nucleic acids from the at least a first selected clone and expressing the nucleic acids in a recombinant host cell to provide the at least a first VEGFR2-blocking, anti-VEGF antibody; and preferably
(e) obtaining the at least a first VEGFR2-blocking, anti-VEGF antibody expressed by the nucleic acids obtained from the at least a first selected clone.
Again, in such phagemid library-based techniques, transgenic animals bearing human antibody gene libraries may be employed, thus yielding recombinant human monoclonal antibodies.
Irrespective of the manner of preparation of a first VEGFR2-blocking, anti-VEGF antibody nucleic acid segment, further suitable antibody nucleic acid segments may be readily prepared by standard molecular biological techniques. In order to confirm that any variant, mutant or second generation VEGFR2-blocking, anti-VEGF antibody nucleic acid segment is suitable for use in the present invention, the nucleic acid segment will be tested to confirm expression of a VEGFR2-blocking, anti-VEGF antibody in accordance with the present invention. Preferably, the variant, mutant or second generation nucleic acid segment will also be tested to confirm hybridization under standard, more preferably, standard stringent hybridization conditions. Exemplary suitable hybridization conditions include hybridization in about 7% sodium dodecyl sulfate (SDS), about 0.5 M NaPO4, about 1 mM EDTA at about 50xc2x0 C.; and washing with about 1% SDS at about 42xc2x0 C.
As a variety of recombinant monoclonal antibodies, whether human or non-human in origin, may be readily prepared, the treatment methods of the invention may be executed by providing to the animal or patient at least a first nucleic acid segment that expresses a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody in the patient. The xe2x80x9cnucleic acid segment that expresses a VEGFR2-blocking, anti-VEGF, 2C3-like or 2C3-based antibodyxe2x80x9d will generally be in the form of at least an expression construct, and may be in the form of an expression construct comprised within a virus or within a recombinant host cell. Preferred gene therapy vectors of the present invention will generally be viral vectors, such as comprised within a recombinant retrovirus, herpes simplex virus (HSV), adenovirus, adeno-associated virus (AAV), cytomegalovirus (CMV), and the like.
This invention further provides compositions comprising at least a first purified VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof optionally one that binds to essentially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595). Such compositions may be pharmaceutically acceptable compositions or compositions for use in laboratory studies. In terms of the pharmaceutical compositions, they may preferably be formulated for parenteral administration, such as for intravenous administration.
The present invention provides a number of methods and uses of the VEGFR2-blocking, anti-VEGF antibodies, including the 2C3-cross-reactive, 2C3-like or 2C3-based antibodies. Concerning all methods, the terms xe2x80x9caxe2x80x9d and xe2x80x9canxe2x80x9d are used to mean xe2x80x9cat least onexe2x80x9d, xe2x80x9cat least a firstxe2x80x9d, xe2x80x9cone or morexe2x80x9d or xe2x80x9ca pluralityxe2x80x9d of steps in the recited methods, except where specifically stated. This is particularly relevant to the administration steps in the treatment methods. Thus, not only may different doses be employed with the present invention, but different numbers of doses, e.g., injections, may be used, up to and including multiple injections. Combined therapeutics may be used, administered before, after or during administration of the anti-VEGF therapeutic antibody.
Various useful in vitro methods and uses are provided that have important biological implications. First provided are methods of, and uses in, binding VEGF, which generally comprise effectively contacting a composition comprising VEGF, preferably free (non-receptor bound) VEGF with at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally an antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
Methods of, and uses in, detecting VEGF are provided, which generally comprise contacting a composition suspected of containing VEGF with at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), under conditions effective to allow the formation of VEGF/antibody complexes and detecting the complexes so formed. The detection methods and uses may be used in connection with biological samples, e.g., in diagnostics for angiogenesis and tumors, and diagnostic kits based hereon are also provided.
The present invention provides methods of, and uses in, preferentially or specifically inhibiting VEGF binding to the VEGF receptor VEGFR2, which generally comprise contacting, in the presence of VEGF, a population of cells or tissues that includes endothelial cells that express VEGFR2 (KDR/Flk-1) with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, under conditions effective to inhibit VEGF binding to the VEGF receptor VEGFR2.
Methods of, and uses in, significantly inhibiting VEGF binding to the VEGF receptor VEGFR2, without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 are provided. These methods comprise contacting, in the presence of VEGF, a population of cells or tissues that includes a population of endothelial cells that express VEGFR2 (KDR/Flk-1) and VEGFR1 (Flt-1) with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally an anti-VEGF antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, under conditions effective to inhibit VEGF binding to the VEGF receptor VEGFR2, without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1.
Further methods and uses of the invention are in analyzing the biological roles of the VEGF receptors termed VEGFR2 and VEGFR1, comprising the steps of:
(a) contacting a biological composition or tissue that comprises VEGF and a population of cells that express VEGFR2 (KDR/Flk-1) and VEGFR1 (Flt-1) receptors with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally an anti-VEGF antibody that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof; and
(b) determining the effect of the VEGFR2-blocking, anti-VEGF antibody on at least a first biological response to VEGF; wherein:
(i) an alteration in a biological response in the presence of the VEGFR2-blocking, anti-VEGF antibody is indicative of a response mediated by the VEGFR2 receptor; and
(ii) the maintenance of a biological response in the presence of the VEGFR2-blocking, anti-VEGF antibody is indicative of a response mediated by the VEGFR1 receptor.
Proliferation inhibition methods and uses are provided, including those to specifically inhibit VEGF-induced endothelial cell proliferation and/or migration, which generally comprise contacting a population of cells or tissues that includes a population of endothelial cells and VEGF with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the VEGFR2-blocking, anti-VEGF antibody, under conditions effective to inhibit VEGF-induced endothelial cell proliferation and/or migration.
Methods of, and uses in, inhibiting VEGF-induced endothelial cell proliferation and/or migration, without significantly inhibiting VEGF-induced macrophage chemotaxis are provided, which generally comprise contacting a population of cells or tissues that contains endothelial cells, macrophages and VEGF with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the anti-VEGF antibody, under conditions effective to inhibit VEGF-induced endothelial cell proliferation and/or migration, without significantly inhibiting VEGF-induced macrophage chemotaxis.
Methods of, and uses in, inhibiting VEGF-induced endothelial cell proliferation and/or migration and, optionally, angiogenesis, without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts are further provided. The methods generally comprise contacting a population of cells or tissues that contain endothelial cells and at least one of macrophages, osteoclasts or chondroclasts, with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the antibody, under conditions effective to inhibit VEGF-induced endothelial cell proliferation and/or migration or angiogenesis, without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts.
The foregoing methods and uses can be performed in vitro and in vivo, in the latter case, wherein the tissues or cells are located within an animal and the anti-VEGF antibody is administered to the animal. In both cases, the methods and uses become methods and uses for inhibiting angiogenesis, comprising contacting a tissue comprising, or a population of, potentially angiogenic blood vessels, i e., those potentially exposed to VEGF, with an anti-angiogenic composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, under conditions effective to inhibit angiogenesis.
Where populations of potentially angiogenic blood vessels are maintained ex vivo, the present invention has utility in drug discovery programs. In vitro screening assays, with reliable positive and negative controls, are useful as a first step in the development of drugs to inhibit or promoter angiogenesis, as well as in the delineation of further information on the angiogenic process. Where the population of potentially angiogenic blood vessels is located within an animal or patient, the anti-angiogenic composition is administered to the animal as a form of therapy.
xe2x80x9cBiologically effective amountsxe2x80x9d, in terms of each of the foregoing inhibitory methods are therefore amounts of VEGFR2-blocking, anti-VEGF antibodies, optionally 2C3-based antibodies, effective to inhibit VEGF-induced endothelial cell proliferation and/or migration; to inhibit VEGF-induced endothelial cell proliferation and/or migration, without significantly inhibiting VEGF-induced macrophage chemotaxis; to inhibit VEGF-induced endothelial cell proliferation and/or migration or angiogenesis, without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts; and, overall, to reduce vascular endothelial cell proliferation and/or migration in a manner effective to inhibit blood vessels growth or angiogenesis.
The invention thus provides methods of, and uses in, inhibiting VEGF-induced angiogenesis and, preferably, treating an angiogenic disease, without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts. The methods generally comprise contacting a population of cells or tissues that contain endothelial cells and at least one of macrophages, osteoclasts or chondroclasts, with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the antibody, under conditions effective to inhibit VEGF-induced angiogenesis and to treat an angiogenic disease without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts.
Methods of, and uses in, inhibiting VEGF-induced angiogenesis and, preferably, treating an anti-angiogenic disease, without causing significant side effects on bone metabolism are further provided. The methods generally comprise contacting a tissue or a population of angiogenic vessels that contain vascular endothelial cells and at least one of macrophages, osteoclasts or chondroclasts, with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the antibody, under conditions effective to inhibit VEGF-induced angiogenesis and to treat an angiogenic disease without causing significant side effects on bone metabolism by not significantly impairing the activities of macrophages, osteoclasts or chondroclasts.
Anti-angiogenic drug screening (in vitro) and therapy (in vivo) are provided in terms of animals and patients that have, or are at risk for developing, any disease or disorder characterized by undesired, inappropriate, aberrant, excessive and/or pathological vascularization. It is well known to those of ordinary skill in the art that as aberrant angiogenesis occurs in a wide range of diseases and disorders, a given anti-angiogenic therapy, once shown to be effective in any acceptable model system, can be used to treat the entire range of diseases and disorders connected with angiogenesis.
The methods and uses of the present invention are particularly intended for use in animals and patients that have, or are at risk for developing, any form of vascularized tumor; macular degeneration, including age-related macular degeneration; arthritis, including rheumatoid arthritis; atherosclerosis and atherosclerotic plaques; diabetic retinopathy and other retinopathies; thyroid hyperplasias, including Grave""s disease; hemangioma; neovascular glaucoma; and psoriasis.
The methods and uses of the invention are further intended for the treatment of animals and patients that have, or are at risk for developing, arteriovenous malformations (AVM), meningioma, and vascular restenosis, including restenosis following angioplasty. Other intended targets of the therapeutic methods and uses are animals and patients that have, or are at risk for developing, angiofibroma, dermatitis, endometriosis, hemophilic joints, hypertrophic scars, inflammatory diseases and disorders, pyogenic granuloma, scleroderma, synovitis, trachoma and vascular adhesions.
As disclosed in U.S. Pat. No. 5,712,291, specifically incorporated herein by reference, each of the foregoing somewhat preferred treatment groups are by no means exhaustive of the types of conditions that are to be treated by the present invention. U.S. Pat. No. 5,712,291 is incorporated herein by reference for certain specific purposes, including the purpose of identifying a number of other conditions that may be effectively treated by an anti-angiogenic therapeutic; the purpose of showing that the treatment of all angiogenic diseases represents a unified concept, once a defined category of angiogenesis-inhibiting compounds have been disclosed and claimed (in the present case, VEGFR2-blocking, anti-VEGF antibodies, optionally those that bind to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595)); and the purpose of showing that the treatment of all angiogenic diseases is enabled by data from only a single model system.
In yet further aspects, and as disclosed in U.S. Pat. No. 5,712,291, incorporated herein by reference, the methods and uses of the present invention are intended for the treatment of animals and patients that have, or are at risk for developing, abnormal proliferation of fibrovascular tissue, acne rosacea, acquired immune deficiency syndrome, artery occlusion, atopic keratitis, bacterial ulcers, Bechets disease, blood borne tumors, carotid obstructive disease, chemical bums, choroidal neovascularization, chronic inflammation, chronic retinal detachment, chronic uveitis, chronic vitritis, contact lens overwear, corneal graft rejection, corneal neovascularization, corneal graft neovascularization, Crohn""s disease, Eales disease, epidemic keratoconjunctivitis, fungal ulcers, Herpes simplex infections, Herpes zoster infections, hyperviscosity syndromes, Kaposi""s sarcoma, leukemia, lipid degeneration, Lyme""s disease, marginal keratolysis, Mooren ulcer, Mycobacteria infections other than leprosy, myopia, ocular neovascular disease, optic pits, Osler-Weber syndrome (Osler-Weber-Rendu, osteoarthritis, Pagets disease, pars planitis, pemphigoid, phylectenulosis, polyarteritis, post-laser complications, protozoan infections, pseudoxanthoma elasticum, pterygium keratitis sicca, radial keratotomy, retinal neovascularization, retinopathy of prematurity, retrolental fibroplasias, sarcoid, scleritis, sickle cell anemia, Sogrens syndrome, solid tumors, Stargarts disease, Steven""s Johnson disease, superior limbic keratitis, syphilis, systemic lupus, Terrien""s marginal degeneration, toxoplasmosis, trauma, tumors of Ewing sarcoma, tumors of neuroblastoma, tumors of osteosarcoma, tumors of retinoblastoma, tumors of rhabdomyosarcoma, ulceritive colitis, vein occlusion, Vitamin A deficiency and Wegeners sarcoidosis.
The present invention further provides methods and uses for the treatment of animals and patients that have, or are at risk for developing, arthritis, in common with the treatment of arthritis using immunological agents described in U.S. Pat. No. 5,753,230, specifically incorporated herein by reference. U.S. Pat. No. 5,972,922 is also specifically incorporated herein by reference to even further exemplify the application of anti-angiogenic strategies to the treatment of undesired angiogenesis associated with diabetes, parasitic diseases, abnormal wound healing, hypertrophy following surgery, burns, injury or trauma, inhibition of hair growth, inhibition of ovulation and corpus luteum formation, inhibition of implantation and inhibition of embryo development in the uterus. All of the foregoing conditions are therefore contemplated for treatment by the methods and uses of the present invention.
U.S. Pat. No. 5,639,757 is further specifically incorporated herein by reference to exemplify the use of anti-angiogenic strategies to the general treatment of graft rejection. The treatment of lung inflammation, nephrotic syndrome, preeclampsia, pericardial effusion, such as that associated with pericarditis, and pleural effusion using anti-angiogenic strategies based upon VEGF inhibition is described in WO 98/45331, specifically incorporated herein by reference. Animals and patients that have, or are at risk for developing, any of the foregoing conditions are therefore contemplated for treatment by the methods and uses of the present invention.
As disclosed in WO 98/16551, specifically incorporated herein by reference, biological molecules that antagonize VEGF function are also suitable for use in treating diseases and disorders characterized by undesirable vascular permeability. Accordingly, the VEGF antagonizing antibodies, methods and uses of the present invention are applicable to the treatment of animals and patients that have, or are at risk for developing, diseases and disorders characterized by undesirable vascular permeability, e.g., edema associated with brain tumors, ascites associated with malignancies, Meigs"" syndrome, lung inflammation, nephrotic syndrome, pericardial effusion and pleural effusion and the like.
Although the treatment of all the foregoing diseases is enabled within the present, unified invention, a particularly preferred aspect of the methods and uses of the present invention is application of anti-angiogenic therapy to animals and patients that have, or are at risk for developing, a vascularized solid tumor, a metastatic tumor or metastases from a primary tumor.
Methods of, and uses in, inhibiting VEGF-induced angiogenesis, and, preferably, exerting an anti-tumor or improved anti-tumor effect without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts are further provided. The methods generally comprise contacting a tissue, tumor environment or population of angiogenic vessels that contain vascular endothelial cells and at least one of macrophages, osteoclasts or chondroclasts, with a composition comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment of the antibody, under conditions effective to inhibit VEGF-induced angiogenesis and to exert an anti-tumor or improved anti-tumor effect without significantly inhibiting VEGF stimulation of macrophages, osteoclasts or chondroclasts.
The present invention thus further provides methods of, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, comprising administering to an animal or patient with such a disease or cancer a therapeutically effective amount of at least a first pharmaceutical composition that comprises a VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment or immunoconjugate of such an anti-VEGF antibody.
This invention links both anti-angiogenic methods using unconjugated or naked antibodies and fragments thereof, and vascular targeting methods using immunoconjugates in which the antibody, or antigen-binding fragment thereof, is operatively attached to a therapeutic agent. Unless otherwise specifically stated or made clear in scientific terms, the terms xe2x80x9cantibody and fragment thereof, as used herein, therefore mean an xe2x80x9cunconjugated or nakedxe2x80x9d antibody or fragment, which is not attached to another agent, particularly a therapeutic or diagnostic agent. These definitions do not exclude modifications of the antibody, such as, by way of example only, modifications to improve the biological half life, affinity, avidity or other properties of the antibody, or combinations of the antibody with other effectors.
The anti-angiogenic treatment methods and uses of the invention also encompass the use of both unconjugated or naked antibodies and immunoconjugates. In the immunoconjugate-based anti-angiogenic treatment methods, the antibody, or antigen-binding fragment thereof, is preferably operatively attached to a second anti-angiogenic agent (the anti-VEGF antibody itself, being the first anti-angiogenic agent). The attached anti-angiogenic agents may be those that have a direct or indirect anti-angiogenic effect.
The anti-angiogenic treatment methods and uses comprise administering to an animal or patient with a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, a therapeutically effective amount of at least a first pharmaceutical composition that comprises at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595). Equally, the administered antibody may be operatively associated with a second anti-angiogenic agent.
Methods for, and uses in, treating metastatic cancer comprise administering to an animal or patient with metastatic cancer a therapeutically effective amount of at least a first pharmaceutical composition that comprises at least a first an unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595). Further methods are those wherein the administered antibody may be operatively associated with a second anti-angiogenic agent.
Methods for, and uses in, reducing metastases from a primary cancer comprise administering a therapeutically effective amount of at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, to an animal or patient that has, or was treated for, a primary cancer; wherein the unconjugated or naked VEGFR2-blocking, anti-VEGF antibody or fragment thereof optionally binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595). Similarly, the administered antibody may be operatively associated with a second anti-angiogenic agent.
Methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, further comprise administering to an animal or patient with such a disease, e.g., a vascularized tumor, at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, in an amount effective to inhibit angiogenesis within the disease site or vascularized tumor. Equally, the administered antibody may be operatively associated with a second anti-angiogenic agent.
The methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, further comprise administering to an animal or patient with such a disease or cancer at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, in an amount effective to inhibit VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1), thereby inhibiting angiogenesis within the disease or cancerous site. The administered antibody may alternatively be operatively associated with a second anti-angiogenic agent.
Methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, also comprise administering to an animal or patient with a vascularized tumor a therapeutically effective amount of at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or antigen-binding fragment thereof; wherein the anti-VEGF antibody substantially inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1). Equally, the administered antibody may be operatively associated with a second anti-angiogenic agent.
Yet further methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, comprise administering to an animal or patient with such a disease, cancer or vascularized tumor a therapeutically effective amount of at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof; wherein the anti-VEGF antibody substantially inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1), thereby inhibiting angiogenesis within the disease site, cancer or vascularized tumor without significantly impairing macrophage chemotaxis in the animal. The administered antibody may also be operatively associated with a second anti-angiogenic agent.
Still further methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, comprise administering to an animal or patient with such a disease, cancer or vascularized tumor a therapeutically effective amount of at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof; wherein the anti-VEGF antibody substantially inhibits VEGF binding to the VEGF receptor VEGFR2 (KDR/Flk-1) without significantly inhibiting VEGF binding to the VEGF receptor VEGFR1 (Flt-1), thereby inhibiting angiogenesis within the disease site, cancer or vascularized tumor without significantly impairing macrophage, osteoclast and/or chondroclast activity in the animal. Equally, the administered antibody may be operatively associated with a second anti-angiogenic agent.
Methods for, and uses in, treating a disease associated with angiogenesis, including all forms of cancer associated with angiogenesis, further comprise administering to an animal or patient with such a disease, e.g., a vascularized tumor, at least a first unconjugated or naked VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof, in an amount effective to inhibit angiogenesis within the disease site or vascularized tumor without exerting a significant adverse on bone metabolism.
The foregoing anti-angiogenic treatment methods and uses will generally involve the administration of the pharmaceutically effective composition to the animal or patient systemically, such as by transdermal, intramuscular, intravenous injection and the like. However, any route of administration that allows the therapeutic agent to localize to the angiogenic site or sites, including tumor or intratumoral vascular endothelial cells, will be acceptable. Therefore, other suitable routes of delivery include oral, rectal, nasal, topical, and vaginal. U.S. Pat. No. 5,712,291, is specifically incorporated herein by reference for purposes including further describing the various routes of administration that may be included in connection with the treatment of an angiogenic disease or disorder.
For uses and methods for the treatment of arthritis, e.g., intrasynovial administration may be employed, as described for other immunological agents in U.S. Pat. No. 5,753,230, specifically incorporated herein by reference. For conditions associated with the eye, ophthalmic formulations and administration are contemplated.
xe2x80x9cAdministrationxe2x80x9d, as used herein, means provision or delivery of VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics in an amount(s) and for a period of time(s) effective to exert anti-angiogenic and/or anti-tumor effects. The passive administration of proteinaceous therapeutics is generally preferred, in part, for its simplicity and reproducibility.
However, the term xe2x80x9cadministrationxe2x80x9d is herein used to refer to any and all means by which VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics are delivered or otherwise provided to the tumor vasculature. xe2x80x9cAdministrationxe2x80x9d therefore includes the provision of cells that produce the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics in a manner effective to result in delivery to the tumor. In such embodiments, it may be desirable to formulate or package the cells in a selectively permeable membrane, structure or implantable device, generally one that can be removed to cease therapy. Exogenous VEGFR2-blocking, anti-VEGF antibody or 2C3-like administration will still generally be preferred, as this represents a non-invasive method that allows the dose to be closely monitored and controlled.
The therapeutic methods and uses of the invention also extend to the provision of nucleic acids that encode VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics in a manner effective to result in their expression in the vicinity of the tumor or their localization to the tumor. Any gene therapy technique may be employed, such as naked DNA delivery, recombinant genes and vectors, cell-based delivery, including ex vivo manipulation of patients"" cells, and the like.
In yet further embodiments, the invention provides methods for, and uses in, delivering selected therapeutic or diagnostic agents to angiogenic blood vessels associated with disease. Such embodiments are preferably used for delivering selected therapeutic or diagnostic agents to tumor or intratumoral vasculature or stroma, and comprise administering to an animal or patient having a vascularized tumor a biologically effective amount of a composition comprising at least a first immunoconjugate in which a diagnostic or therapeutic agent is operatively attached to a VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595).
Although understanding the mechanism of action underlying the targeting aspects of the invention is not required in order to practice such embodiments, it is believed that the antibodies of the invention deliver attached agents to angiogenic and tumor vasculature by virtue of binding to VEGF bound to the VEGFR1 expressed thereon. These methods and uses of the invention thus concern delivering selected therapeutic or diagnostic agents to angiogenic blood vessels, tumor or intratumoral vasculature, and comprise administering to an animal or patient in need of treatment a biologically effective amount of a composition comprising an immunoconjugate in which a diagnostic or therapeutic agent is operatively attached to at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), in a manner effective to allow binding of the antibody to VEGF bound to VEGFR1 expressed, overexpressed or upregulated on the angiogenic blood vessels, tumor or intratumoral vasculature, thus delivering the diagnostic or therapeutic agent to the VEGF-VEGFR1 on the angiogenic blood vessels, tumor or intratumoral vasculature.
The delivery of selected therapeutic agents to tumor or intratumoral vasculature or stroma acts to arrest blood flow, or specifically arrest blood flow, in tumor vasculature; to destroy, or specifically destroy, tumor vasculature; and to induce necrosis, or specific necrosis in a tumor. These methods and uses may thus be summarized as methods for treating an animal or patient having a vascularized tumor, comprising administering to the animal or patient a therapeutically effective amount of at least a first pharmaceutical composition comprising at least a first immunoconjugate that comprises a VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or antigen-binding fragment thereof, operatively attached to a therapeutic agent.
The xe2x80x9ctherapeutically effective amountsxe2x80x9d for use in the invention are amounts of VEGFR2-blocking, anti-VEGF antibody or 2C3-based immunoconjugates effective to specifically kill at least a portion of tumor or intratumoral vascular endothelial cells; to specifically induce apoptosis in at least a portion of tumor or intratumoral vascular endothelial cells; to specifically promote coagulation in at least a portion of tumor or intratumoral blood vessels; to specifically occlude or destroy at least a portion of blood transporting vessels of the tumor; to specifically induce necrosis in at least a portion of a tumor; and/or to induce tumor regression or remission upon administration to selected animals or patients. Such effects are achieved while exhibiting little or no binding to, or little or no killing of, vascular endothelial cells in normal, healthy tissues; little or no coagulation in, occlusion or destruction of blood vessels in healthy, normal tissues; and exerting negligible or manageable adverse side effects on normal, healthy tissues of the animal or patient.
The terms xe2x80x9cpreferentiallyxe2x80x9d and xe2x80x9cspecificallyxe2x80x9d, as used herein in the context of promoting coagulation in, or destroying, tumor vasculature, and/or in the context of binding to tumor stroma and/or causing tumor necrosis, thus mean that the VEGFR2-blocking, anti-VEGF antibody or 2C3-based immunoconjugates function to achieve stromal binding, coagulation, destruction and/or tumor necrosis that is substantially confined to the tumor stroma, vasculature and tumor site, and does not substantially extend to causing coagulation, destruction and/or tissue necrosis in normal, healthy tissues of the animal or subject. The structure and function of healthy cells and tissues is therefore maintained substantially unimpaired by the practice of the invention.
Although the antibodies of the invention effectively deliver agents to angiogenic and tumor vasculature by binding to VEGF in association with VEGFR1, other methods and uses operate on the basis of delivering a therapeutic agent to tumor stroma, wherein it exerts a therapeutic effect on the nearby vessels. These methods and uses comprise administering to an animal or patient with a vascularized tumor an immunoconjugate that comprises a therapeutic agent operatively attached to at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) in an amount effective to bind the immunoconjugate to non-receptor bound VEGF within the tumor stroma.
These methods and uses comprise administering to an animal or patient with a vascularized tumor an immunoconjugate that comprises a therapeutic agent operatively attached to at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595) in an amount effective to localize the immunoconjugate within the tumor stroma such that the attached therapeutic agent exerts an anti-tumor effect on the surrounding tumor vasculature and/or tumor cells.
The compositions, as well as the methods and uses, of the invention thus extend to compositions comprising VEGFR2-blocking, anti-VEGF antibody or 2C3-based immunoconjugates comprising at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), operatively attached to at least a first therapeutic or diagnostic agent. VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic conjugates are preferably linked to radiotherapeutic agents, anti-angiogenic agents, apoptosis-inducing agents, anti-tubulin drugs, anti-cellular or cytotoxic agents, or coagulants (coagulation factors).
The invention thus provides a range of conjugated antibodies and fragments thereof in which the antibody is operatively attached to at least a first therapeutic or diagnostic agent. The term xe2x80x9cimmunoconjugatexe2x80x9d is broadly used to define the operative association of the antibody with another effective agent and is not intended to refer solely to any type of operative association, and is particularly not limited to chemical xe2x80x9cconjugationxe2x80x9d. Recombinant fusion proteins are particularly contemplated. So long as the delivery or targeting agent is able to bind to the target and the therapeutic or diagnostic agent is sufficiently functional upon delivery, the mode of attachment will be suitable.
Attachment of agents via the carbohydrate moieties on antibodies is also contemplated. Glycosylation, both O-linked and N-linked, naturally occurs in antibodies. Recombinant antibodies can be modified to recreate or create additional glycosylation sites if desired, which is simply achieved by engineering the appropriate amino acid sequences (such as Asn-X-Ser, Asn-X-Thr, Ser, or Thr) into the primary sequence of the antibody.
Currently preferred agents for use in VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic conjugates and related methods and uses are those that complement or enhance the effects of the antibody and/or those selected for a particular tumor type or patient. xe2x80x9cTherapeutic agents that complement or enhance the effects of the antibodyxe2x80x9d include radiotherapeutic agents, anti-angiogenic agents, apoptosis-inducing agents and anti-tubulin drugs, any one or more of which are preferred for use herewith.
The attachment or association of the preferred agents with VEGFR2-blocking, anti-VEGF or 2C3-based antibodies gives xe2x80x9cimmunoconjugatesxe2x80x9d, wherein such immunoconjugates often have enhanced and even synergistic anti-tumor properties. Currently preferred anti-angiogenic agents for use in this manner are angiostatin, endostatin, any one of the angiopoietins, vasculostatin, canstatin and maspin. Currently preferred anti-tubulin drugs include colchicine, taxol, vinblastine, vincristine, vindescine and one or more of the combretastatins.
The use of anti-cellular and cytotoxic agents results in VEGFR2-blocking, anti-VEGF antibody or 2C3-based xe2x80x9cimmunotoxinsxe2x80x9d, whereas the use of coagulation factors results in VEGFR2-blocking, anti-VEGF antibody or 2C3-based xe2x80x9ccoaguligandsxe2x80x9d. The use of at least two therapeutic agents is also contemplated, such as combinations of one or more radiotherapeutic agents, anti-angiogenic agents, apoptosis-inducing agents, anti-tubulin drugs, anti-cellular and cytotoxic agents and coagulation factors.
In certain applications, the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics will be operatively attached to cytotoxic, cytostatic or otherwise anti-cellular agents that have the ability to kill or suppress the growth or cell division of endothelial cells. Suitable anti-cellular agents include chemotherapeutic agents, as well as cytotoxins and cytostatic agents. Cytostatic agents are generally those that disturb the natural cell cycle of a target cell, preferably so that the cell is taken out of the cell cycle.
Exemplary chemotherapeutic agents include: steroids; cytokines; anti-metabolites, such as cytosine arabinoside, fluorouracil, methotrexate or aminopterin; anthracyclines; mitomycin C; vinca alkaloids; antibiotics; demecolcine; etoposide; mithramycin; and anti-tumor alkylating agents, such as chlorambucil or melphalan. Indeed, any of the agents disclosed herein in Table C could be used. Certain preferred anti-cellular agents are DNA synthesis inhibitors, such as daunorubicin, doxorubicin, adriamycin, and the like.
In certain therapeutic applications, toxin moieties will be preferred, due to the much greater ability of most toxins to deliver a cell killing effect, as compared to other potential agents. Therefore, certain preferred anti-cellular agents for VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody constructs are plant-, fungus- or bacteria-derived toxins. Exemplary toxins include epipodophyllotoxins; bacterial endotoxin or the lipid A moiety of bacterial endotoxin; ribosome inactivating proteins, such as saporin or gelonin; a-sarcin; aspergillin; restrictocin; ribonucleases, such as placental ribonuclease; diphtheria toxin and pseudomonas exotoxin.
Preferred toxins are the A chain toxins, such as ricin A chain. The most preferred toxin moiety is often ricin A chain that has been treated to modify or remove carbohydrate residues, so called xe2x80x9cdeglycosylated A chainxe2x80x9d (dgA). Deglycosylated ricin A chain is preferred because of its extreme potency, longer half-life, and because it is economically feasible to manufacture it a clinical grade and scale. Recombinant and/or truncated ricin A chain may also be used.
For tumor targeting and treatment with immunotoxins, the following patents and patent applications are specifically incorporated herein by reference for the purposes of even further supplementing the present teachings regarding anti-cellular and cytotoxic agents: U.S. application Ser. Nos. 07/846,349; 08/295,868 (U.S. Pat. No. 6,004,554); 08/205,330 (U.S. Pat. No. 5,855,866); 08/350,212 (U.S. Pat. No. 5,965,132); 08/456,495 (U.S. Pat. No. 5,776,427); 08/457,487 (U.S. Pat. No. 5,863,538); 08/457,229 and 08/457,031 (U.S. Pat. No. 5,660,827) and 08/457,869 (U.S. Pat. No. 6,051,230).
The 2C3-based or other VEGFR2-blocking, anti-VEGF antibody of the present invention may be linked to an anti-tubulin drug. xe2x80x9cAnti-tubulin drug(s)xe2x80x9d, as used herein, means any agent, drug, prodrug or combination thereof that inhibits cell mitosis, preferably by directly or indirectly inhibiting tubulin activities necessary for cell mitosis, preferably tubulin polymerization or depolymerization.
Currently preferred anti-tubulin drugs for use herewith are colchicine; taxanes, such as taxol; vinca alkaloids, such as vinblastine, vincristine and vindescine; and combretastatins. Exemplary combretastatins are combretastatin A, B and/or D, including A-1, A-2, A-3, A-4, A-5, A-6, B-1, B-2, B-3, B-4, D-1 and D-2 and prodrug forms thereof.
The VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics may comprise a component that is capable of promoting coagulation, i.e., a coagulant. Here, the targeting antibody may be directly or indirectly, e.g., via another antibody, linked to a factor that directly or indirectly stimulates coagulation.
Preferred coagulation factors for such uses are Tissue Factor (TF) and TF derivatives, such as truncated TF (tTF), dimeric, trimeric, polymeric/multimeric TF, and mutant TF deficient in the ability to activate Factor VII. Other suitable coagulation factors include vitamin K-dependent coagulants, such as Factor II/IIa, Factor VII/VIIa, Factor IX/IXa and Factor X/Xa; vitamin K-dependent coagulation factors that lack the Gla modification; Russell""s viper venom Factor X activator; platelet-activating compounds, such as thromboxane A2 and thromboxane A2 synthase; and inhibitors of fibrinolysis, such as xcex12-antiplasmin.
Tumor targeting and treatment with coaguligands is described in the following patents and patent applications, each of which are specifically incorporated herein by reference for the purposes of even further supplementing the present teachings regarding coaguligands and coagulation factors: U.S. application Serial Nos. 07/846,349; 08/205,330 (U.S. Pat. No. 5,855,866); 08/350,212 (U.S. Pat. No. 5,965,132); 08/273,567; 08/482,369 (U.S. Pat. No. 6,093,399); Oct. 20, 1998); 08/485,482; 08/487,427 (U.S. Pat. No. 6,004,555); 08/479,733 (U.S. Pat. No. 5,877,289); 08/472,631; and 08/479,727 and 08/481,904 (U.S. Pat. No. 6,036,955).
The preparation of immunoconjugates and immunotoxins is generally well known in the art (see, e.g., U.S. Pat. No. 4,340,535, incorporated herein by reference). Each of the following patents and patent applications are further incorporated herein by reference for the purposes of even further supplementing the present teachings regarding immunotoxin generation, purification and use: U.S. applications Ser. No. 07/846,349; 08/295,868 (U.S. Pat. No. 6,004,554); 08/205,330 (U.S. Pat. No. 5,855,866); 08/350,212 (U.S. Pat. No. 5,965,132); 08/456,495 (U.S. Pat. No. 5,776,427); 08/457,487 (U.S. Pat. No. 5,863,538); 08/457,229 and 08/457,031 (U.S. Pat. No. 5,660,827) and 08/457,869 (U.S. Pat. No. 6,051,230).
In the preparation of immunoconjugates and immunotoxins, advantages may be achieved through the use of certain linkers. For example, linkers that contain a disulfide bond that is sterically xe2x80x9chinderedxe2x80x9d are often preferred, due to their greater stability in vivo, thus preventing release of the toxin moiety prior to binding at the site of action. It is generally desired to have a conjugate that will remain intact under conditions found everywhere in the body except the intended site of action, at which point it is desirable that the conjugate have good xe2x80x9creleasexe2x80x9d characteristics.
Depending on the specific toxin compound used, it may be necessary to provide a peptide spacer operatively attaching the VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody and the toxin compound, wherein the peptide spacer is capable of folding into a disulfide-bonded loop structure. Proteolytic cleavage within the loop would then yield a heterodimeric polypeptide wherein the antibody and the toxin compound are linked by only a single disulfide bond.
When certain other toxin compounds are utilized, a non-cleavable peptide spacer may be provided to operatively attach the VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody and the toxin compound. Toxins that may be used in conjunction with non-cleavable peptide spacers are those that may, themselves, be converted by proteolytic cleavage, into a cytotoxic disulfide-bonded form. An example of such a toxin compound is a Pseudonomas exotoxin compound.
A variety of chemotherapeutic and other pharmacological agents can also be successfully conjugated to VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutics. Exemplary antineoplastic agents that have been conjugated to antibodies include doxorubicin, daunomycin, methotrexate and vinblastine. Moreover, the attachment of other agents such as neocarzinostatin, macromycin, trenimon and (xcex1-amanitin has been described (see U.S. Pat. Nos. 5,660,827; 5,855,866; and 5,965,132; each incorporated herein.)
In light of one of the present inventors earlier work, the preparation of coaguligands is now also easily practiced. The operable association of one or more coagulation factors with a VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody may be a direct linkage, such as those described above for the immunotoxins. Alternatively, the operative association may be an indirect attachment, such as where the antibody is operatively attached to a second binding region, preferably an antibody or antigen binding region of an antibody, that binds to the coagulation factor. The coagulation factor should be attached to the VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody at a site distinct from its functional coagulating site, particularly where a covalent linkage is used to join the molecules.
Indirectly linked coaguligands are often based upon bispecific antibodies. The preparation of bispecific antibodies is also well known in the art. One preparative method involves the separate preparation of antibodies having specificity for the targeted tumor component, on the one hand, and the coagulating agent on the other. Peptic F(abxe2x80x2xcex3)2 fragments from the two chosen antibodies are then generated, followed by reduction of each to provide separate Fabxe2x80x2xcex3SH fragments. The SH groups on one of the two partners to be coupled are then alkylated with a cross-linking reagent, such as o-phenylenedimaleimide, to provide free maleimide groups on one partner. This partner may then be conjugated to the other by means of a thioether linkage, to give the desired F(abxe2x80x2xcex3)2 heteroconjugate (Glennie et al, 1987; incorporated herein by reference). Other approaches, such as cross-linking with SPDP or protein A may also be carried out.
Another method for producing bispecific antibodies is by the fusion of two hybridomas to form a quadroma. As used herein, the term xe2x80x9cquadromaxe2x80x9d is used to describe the productive fusion of two B cell hybridomas. Using now standard techniques, two antibody producing hybridomas are fused to give daughter cells, and those cells that have maintained the expression of both sets of clonotype immunoglobulin genes are then selected.
A preferred method of generating a quadroma involves the selection of an enzyme deficient mutant of at least one of the parental hybridomas. This first mutant hybridoma cell line is then fused to cells of a second hybridoma that had been lethally exposed, e.g., to iodoacetamide, precluding its continued survival. Cell fusion allows for the rescue of the first hybridoma by acquiring the gene for its enzyme deficiency from the lethally treated hybridoma, and the rescue of the second hybridoma through fusion to the first hybridoma. Preferred, but not required, is the fusion of immunoglobulins of the same isotype, but of a different subclass. A mixed subclass antibody permits the use if an alternative assay for the isolation of a preferred quadroma.
Microtiter identification embodiments, FACS, immunofluorescence staining, idiotype specific antibodies, antigen binding competition assays, and other methods common in the art of antibody characterization may be used to identify preferred quadromas. Following the isolation of the quadroma, the bispecific antibodies are purified away from other cell products. This may be accomplished by a variety of antibody isolation procedures, known to those skilled in the art of immunoglobulin purification (see, e.g., Antibodies: A Laboratory Manual, 1988; incorporated herein by reference). Protein A or protein G sepharose columns are preferred.
In the preparation of immunoconjugates, immunotoxins and coaguligands, recombinant expression may be employed. The nucleic acid sequences encoding the chosen VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody, and therapeutic agent, toxin or coagulant, are attached in-frame in an expression vector. Recombinant expression thus results in translation of the nucleic acid to yield the desired immunoconjugate. Chemical cross-linkers and avidin:biotin bridges may also join the therapeutic agents to the VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibodies.
The following patents and patent applications are each incorporated herein by reference for the purposes of even further supplementing the present teachings regarding coaguligand preparation, purification and use, including bispecific antibody coaguligands: U.S. application Ser. Nos. 07/846,349; 08/205,330 (U.S. Pat. No. 5,855,866); 08/350,212 (U.S. Pat. No. 5,965,132); 08/273,567; 08/482,369 (U.S. Pat. No. 6,093,399; Oct. 20, 1998); 08/485,482; 08/487,427 (U.S. Pat. No. 6,004,555); 08/479,733 (U.S. Pat. No. 5,877,289); 08/472,631; and 08/479,727 and 08/481,904 (U.S. Pat. No. 6,036,955).
Immunoconjugates with radiotherapeutic agents, anti-angiogenic agents, apoptosis-inducing agents, anti-tubulin drugs, toxins and coagulants, whether prepared by chemical conjugation or recombinant expression, may employ a biologically-releasable bond and/or a selectively cleavable spacer or linker. Such compositions are preferably reasonably stable during circulation and are preferentially or specifically released upon delivery to the disease or tumor site.
Certain preferred examples are acid sensitive spacers, wherein VEGFR2-blocking, anti-VEGF antibodies linked to colchicine or doxorubicin are particularly contemplated. Other preferred examples are peptide linkers that include a cleavage site for peptidases and/or proteinases that are specifically or preferentially present or active within a disease site, such as a tumor environment. The delivery of the immunoconjugate to the disease or tumor site results in cleavage and the relatively specific release of the coagulation factor.
Peptide linkers that include a cleavage site for urokinase, pro-urokinase, plasmin, plasminogen, TGFxcex2, staphylokinase, Thrombin, Factor IXa, Factor Xa or a metalloproteinase (MMP), such as an interstitial collagenase, a gelatinase or a stromelysin, are particularly preferred, as described and enabled by U.S. Pat. No. 5,877,289, incorporated herein by reference for such purposes, and further exemplified herein in Table B2.
The VEGFR2-blocking, anti-VEGF antibody may also be derivatized to introduce functional groups permitting the attachment of the therapeutic agent(s) through a biologically releasable bond. The targeting antibody may thus be derivatized to introduce side chains terminating in hydrazide, hydrazine, primary amine or secondary amine groups. Therapeutic agents may be conjugated through a Schiff""s base linkage, a hydrazone or acyl hydrazone bond or a hydrazide linker (U.S. Pat. Nos. 5,474,765 and 5,762,918, each specifically incorporated herein by reference).
Whether primarily anti-angiogenic or vascular-targeting based, the compositions and methods of the present invention may be used in combination with other therapeutics and diagnostics. In terms of biological agents, preferably diagnostic or therapeutic agents, for use xe2x80x9cin combinationxe2x80x9d with a VEGFR2-blocking, anti-VEGF antibody in accordance with the present invention, such as a 2C3-based antibody, the term xe2x80x9cin combinationxe2x80x9d is succinctly used to cover a range of embodiments. The xe2x80x9cin combinationxe2x80x9d terminology, unless otherwise specifically stated or made clear from the scientific terminology, thus applies to various formats of combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses.
The xe2x80x9ccombinedxe2x80x9d embodiments of the invention thus include, for example, where the VEGFR2-blocking, anti-VEGF or 2C3-based antibody is a naked antibody and is used in combination with an agent or therapeutic agent that is not operatively attached thereto. In such cases, the agent or therapeutic agent may be used in a non-targeted or targeted form. In xe2x80x9cnon-targeted formxe2x80x9d, the agent, particularly therapeutic agents, will generally be used according to their standard use in the art. In xe2x80x9ctargeted formxe2x80x9d, the agent will generally be operatively attached to a distinct antibody or targeting region that delivers the agent or therapeutic agent to the angiogenic disease site or tumor. The use of such targeted forms of biological agents, both diagnostics and therapeutics, is also quite standard in the art.
In other xe2x80x9ccombinedxe2x80x9d embodiments of the invention, the VEGFR2-blocking, anti-VEGF or 2C3-based antibody is an immunoconjugate wherein the antibody is itself operatively associated or combined with the agent or therapeutic agent. In certain preferred examples, the agent, including diagnostic and therapeutic agents, will be a xe2x80x9c2C3-targeted agentxe2x80x9d. The operative attachment includes all forms of direct and indirect attachment as described herein and known in the art.
The xe2x80x9ccombinedxe2x80x9d uses, particularly in terms of VEGFR2-blocking, anti-VEGF or 2C3-based antibodies in combination with therapeutic agents, also include combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses wherein the therapeutic agent is in the form of a prodrug. In such embodiments, the activating component able to convert the prodrug to the functional form of the drug may again be operatively associated with the VEGFR2-blocking, anti-VEGF or 2C3-based antibodies of the present invention.
In certain preferred embodiments, the therapeutic compositions, combinations, pharmaceuticals, cocktails, kits, methods, and first and second medical uses will be xe2x80x9c2C3-prodrug combinationsxe2x80x9d. As will be understood by those of ordinary skill in the art, the term xe2x80x9c2C3-prodrug combinationxe2x80x9d, unless otherwise stated, means that the 2C3-based antibody is operatively attached to a component capable of converting the prodrug to the active drug, not that the 2C3-based antibody is attached to the prodrug itself. However, there is no requirement that the prodrug embodiments of the invention need to be used as 2C3-prodrug combinations. Accordingly, prodrugs may be used in any manner that they are used in the art, including in ADEPT and other forms.
Thus, where combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses are described, preferably in terms of diagnostic agents, and more preferably therapeutic agents, the combinations include VEGFR2-blocking, anti-VEGF antibodies, such as 2C3-based antibodies, that are naked antibodies and immunoconjugates, and wherein practice of the in vivo embodiments of the invention involves the prior, simultaneous or subsequent administration of the naked antibodies or immunoconjugate and the biological, diagnostic or therapeutic agent; so long as, in some conjugated or unconjugated form, the overall provision of some form of the antibody and some form of the biological, diagnostic or therapeutic agent is achieved.
Particularly preferred combined compositions, methods and uses of the invention are those including VEGFR2-blocking, anti-VEGF antibodies and endostatin (U.S. Pat. No. 5,854,205, specifically incorporated herein by reference). These include where the VEGFR2-blocking, anti-VEGF antibody or 2C3 construct is a naked antibody or immunoconjugate; and when an immunoconjugate, wherein the VEGFR2-blocking, anti-VEGF antibody or 2C3 is linked to endostatin, optionally with angiostatin; wherein the combined therapeutic method or use involves the prior, simultaneous, or subsequent administration of endostatin, optionally with angiostatin; so long as, in some conjugated or unconjugated form, the overall provision of 2C3, endostatin and optionally angiostatin is achieved. VEGFR2-blocking, anti-VEGF or 2C3-based antibodies operatively associated with collagenase are also provided, as the collagenase, when specifically delivered to the tumor, will produce endostatin in situ, achieving similar benefits.
The foregoing and other explanations of the effects of the present invention on tumors are made for simplicity to explain the combined mode of operation, type of attached agent(s) and such like. This descriptive approach should not be interpreted as either an understatement or an oversimplification of the beneficial properties of the VEGFR2-blocking, anti-VEGF antibodies or 2C3-based antibodies of the invention. It will therefore be understood that such antibodies themselves have anti-angiogenic properties and VEGF neutralization properties (such as neutralizing the survival function of VEGF), that immunoconjugates of such antibodies will maintain these properties and combine them with the properties of the attached agent; and further, that the combined effect of the antibody and any attached agent will typically be enhanced and/or magnified.
The invention therefore provides compositions, pharmaceutical compositions, therapeutic kits and medicinal cocktails comprising, optionally in at least a first composition or container, a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment or immunoconjugate of such an anti-VEGF antibody; and a biologically effective amount of at least a second biological agent, component or system.
The xe2x80x9cat least a second biological agent, component or systemxe2x80x9d will often be a therapeutic or diagnostic agent, component or system, but it not be. For example, the at least a second biological agent, component or system may comprise components for modification of the antibody and/or for attaching other agents to the antibody. Certain preferred second biological agents, components or systems are prodrugs or components for making and using prodrugs, including components for making the prodrug itself and components for adapting the antibodies of the invention to function in such prodrug or ADEPT embodiments.
Where therapeutic or diagnostic agents are included as the at least a second biological agent, component or system, such therapeutics and/or diagnostics will typically be those for use in connection with angiogenic diseases. Such agents are those suitable for use in treating or diagnosing a disease or disorder as disclosed in any one of U.S. Pat. Nos. 5,712,291, 5,753,230, 5,972,922, 5,639,757, WO 98/45331 and WO 98/16551, each specifically incorporated herein by reference.
Where the disease to be treated is cancer, xe2x80x9cat least a second anti-cancer agentxe2x80x9d will be included in the therapeutic kit or cocktail. The term xe2x80x9cat least a second anti-cancer agentxe2x80x9d is chosen in reference to the VEGFR2-blocking, anti-VEGF antibody or 2C3 construct being the first anti-cancer agent. The antibodies of the invention may thus be combined with chemotherapeutic agents, radiotherapeutic agents, cytokines, anti-angiogenic agents, apoptosis-inducing agents or anti-cancer immunotoxins or coaguligands.
xe2x80x9cChemotherapeutic agentsxe2x80x9d, as used herein, refer to classical chemotherapeutic agents or drugs used in the treatment of malignancies. This term is used for simplicity notwithstanding the fact that other compounds may be technically described as chemotherapeutic agents in that they exert an anti-cancer effect. However, xe2x80x9cchemotherapeuticxe2x80x9d has come to have a distinct meaning in the art and is being used according to this standard meaning. A number of exemplary chemotherapeutic agents are described herein. Those of ordinary skill in the art will readily understand the uses and appropriate doses of chemotherapeutic agents, although the doses may well be reduced when used in combination with the present invention.
A new class of drugs that may also be termed xe2x80x9cchemotherapeutic agentsxe2x80x9d are agents that induce apoptosis. Any one or more of such drugs, including genes, vectors, antisense constructs and ribozymes, as appropriate, may also be used in conjunction with the present invention. Currently preferred second agents are anti-angiogenic agents, such as angiostatin, endostatin, vasculostatin, canstatin and maspin.
Other exemplary anti-cancer agent include, e.g., neomycin, podophyllotoxin(s), TNF-xcex1, xcex1vxcex23 antagonists, calcium ionophores, calcium-flux inducing agents, and any derivative or prodrug thereof. Currently preferred anti-tubulin drugs include colchicine, taxol, vinblastine, vincristine, vindescine, a combretastatin or a derivative or prodrug thereof.
Anti-cancer immunotoxins or coaguligands are further appropriate anti-cancer agents. xe2x80x9cAnti-cancer immunotoxins or coaguligandsxe2x80x9d, or targeting-agent/therapeutic agent constructs, are based upon targeting agents, including antibodies or antigen binding fragments thereof, that bind to a targetable or accessible component of a tumor cell, tumor vasculature or tumor stroma, and that are operatively attached to a therapeutic agent, including cytotoxic agents (immunotoxins) and coagulation factors (coaguligands). A xe2x80x9ctargetable or accessible componentxe2x80x9d of a tumor cell, tumor vasculature or tumor stroma, is preferably a surface-expressed, surface-accessible or surface-localized component, although components released from necrotic or otherwise damaged tumor cells or vascular endothelial cells may also be targeted, including cytosolic and/or nuclear tumor cell antigens.
Both antibody and non-antibody targeting agents may be used, including growth factors, such as VEGF and FGF; peptides containing the tripeptide R-G-D, that bind specifically to the tumor vasculature; and other targeting components such as annexins and related ligands.
Anti-tumor cell immunotoxins or coaguligands may comprise antibodies exemplified by the group consisting of antibodies termed B3 (ATCC HB 10573), 260F9 (ATCC HB 8488), D612 (ATCC HB 9796) and KS1/4, said KS1/4 antibody obtained from a cell comprising the vector pGKC2310 (NRRL B-18356) or the vector pG2A52 (NRRL B-18357).
Anti-tumor cell targeting agents that comprise an antibody, or an antigen-binding region thereof, that binds to an intracellular component that is released from a necrotic tumor cell are also contemplated. Preferably such antibodies are monoclonal antibodies, or antigen-binding fragments thereof, that bind to insoluble intracellular antigen(s) present in cells that may be induced to be permeable, or in cell ghosts of substantially all neoplastic and normal cells, but are not present or accessible on the exterior of normal living cells of a mammal.
U.S. Pat. Nos. 5,019,368, 4,861,581 and 5,882,626, each issued to Alan Epstein and colleagues, are each specifically incorporated herein by reference for purposes of even further describing and teaching how to make and use antibodies specific for intracellular antigens that become accessible from malignant cells in vivo. The antibodies described are sufficiently specific to internal cellular components of mammalian malignant cells, but not to external cellular components. Exemplary targets include histones, but all intracellular components specifically released from necrotic tumor cells are encompassed.
Upon administration to an animal or patient with a vascularized tumor, such antibodies localize to the malignant cells by virtue of the fact that vascularized tumors naturally contain necrotic tumor cells, due to the process(es) of tumor re-modeling that occur in vivo and cause at least a proportion of malignant cells to become necrotic. In addition, the use of such antibodies in combination with other therapies that enhance tumor necrosis serves to enhance the effectiveness of targeting and subsequent therapy.
These types of antibodies may thus be used to directly or indirectly associate with angiopoietins and to administer the angiopoietins to necrotic malignant cells within vascularized tumors, as generically disclosed herein.
As also disclosed in U.S. Pat. Nos. 5,019,368, 4,861,581 and 5,882,626, each incorporated herein by reference, these antibodies may be used in combined diagnostic methods (see below) and in methods for measuring the effectiveness of anti-tumor therapies. Such methods generally involve the preparation and administration of a labeled version of the antibodies and measuring the binding of the labeled antibody to the internal cellular component target preferentially bound within necrotic tissue. The methods thereby image the necrotic tissue, wherein a localized concentration of the antibody is indicative of the presence of a tumor and indicate ghosts of cells that have been killed by the anti-tumor therapy.
Anti-tumor stroma immunotoxins or coaguligands will generally comprise antibodies that bind to a connective tissue component, a basement membrane component or an activated platelet component; as exemplified by binding to fibrin, RIBS or LIBS.
Anti-tumor vasculature immunotoxins or coaguligands may comprise ligands, antibodies, or fragments thereof, that bind to a surface-expressed, surface-accessible or surface-localized component of the blood transporting vessels, preferably the intratumoral blood vessels, of a vascularized tumor. Such antibodies include those that bind to surface-expressed components of intratumoral blood vessels of a vascularized tumor, including intratumoral vasculature cell surface receptors, such as endoglin (TEC-4 and TEC-11 antibodies), a TGFxcex2 receptor, E-selectin, P-selectin, VCAM-1, ICAM-1, PSMA, a VEGF/VPF receptor, an FGF receptor, a TIE, xcex1vxcex23 integrin, pleiotropin, endosialin and MHC Class II proteins. The antibodies may also bind to cytokine-inducible or coagulant-inducible components of intratumoral blood vessels. Certain preferred agents will bind to aminophospholipids, such as phosphatidylserine or phosphatidylethanolamine.
Other anti-tumor vasculature immunotoxins or coaguligands may comprise antibodies, or fragments thereof, that bind to a ligand or growth factor that binds to an intratumoral vasculature cell surface receptor. Such antibodies include those that bind to VEGF/VPF (GV39 and GV97 antibodies), FGF, TGFxcex2, a ligand that binds to a TIE, a tumor-associated fibronectin isoform, scatter factor/hepatocyte growth factor (HGF), platelet factor 4 (PF4), PDGF and TIMP. The antibodies, or fragments thereof, may also bind to a ligand:receptor complex or a growth factor:receptor complex, but not to the ligand or growth factor, or to the receptor, when the ligand or growth factor or the receptor is not in the ligand:receptor or growth factor:receptor complex.
Anti-tumor cell, anti-tumor stroma or anti-tumor vasculature antibody-therapeutic agent constructs may comprise anti-angiogenic agents, apoptosis-inducing agents, anti-tubulin drugs, cytotoxic agents such as plant-, fungus- or bacteria-derived toxins. Ricin A chain and deglycosylated ricin A chain will often be preferred. Anti-tumor cell, anti-tumor stroma or anti-tumor vasculature antibody-therapeutic agent constructs may comprise coagulants (direct and indirect acting coagulation factors) or second antibody binding regions that bind to coagulation factors. The operative association with Tissue Factor or Tissue Factor derivatives, such as truncated Tissue Factor, will often be preferred.
In terms of compositions, kits and/or medicaments of the invention, the combined effective amounts of the therapeutic agents may be comprised within a single container or container means, or comprised within distinct containers or container means. The cocktails will generally be admixed together for combined use. Agents formulated for intravenous administration will often be preferred. Imaging components may also be included. The kits may also comprise instructions for using the at least a first antibody and the one or more other biological agents included.
Speaking generally, the at least a second anti-cancer agent may be administered to the animal or patient substantially simultaneously with the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic; such as from a single pharmaceutical composition or from two pharmaceutical compositions administered closely together.
Alternatively, the at least a second anti-cancer agent may be administered to the animal or patient at a time sequential to the administration of the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic. xe2x80x9cAt a time sequentialxe2x80x9d, as used herein, means xe2x80x9cstaggeredxe2x80x9d, such that the at least a second anti-cancer agent is administered to the animal or patient at a time distinct to the administration of the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic. Generally, the two agents are administered at times effectively spaced apart to allow the two agents to exert their respective therapeutic effects, i.e., they are administered at xe2x80x9cbiologically effective time intervalsxe2x80x9d. The at least a second anti-cancer agent may be administered to the animal or patient at a biologically effective time prior to the VEGFR2-blocking, anti-VEGF antibody or 2C3-based therapeutic, or at a biologically effective time subsequent to that therapeutic.
Accordingly, the present invention provides methods for treating an animal or patient with a vascularized tumor, comprising:
(a) subjecting the animal or patient to a first treatment that substantially reduces the tumor burden; and
(b) subsequently administering at least a first anti-angiogenic agent to the animal or patient in an amount effective to inhibit metastasis from any surviving tumor cells; wherein the first anti-angiogenic agent is at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595); optionally wherein the antibody or fragment is operatively associated with a second anti-angiogenic agent.
Preferred first treatments include surgical resection and chemotherapeutic intervention. Combined anti-angiogenics can also be used, such as angiopoietin 2 or tumor-targeted angiopoietin 2 constructs.
Other treatment methods for animals or patients with vascularized tumors, comprise:
(a) administering a first antibody-therapeutic agent construct to the animal or patient in an amount effective to induce substantial tumor necrosis; wherein the first antibody-therapeutic agent construct comprises a therapeutic agent operatively linked to a first antibody, or antigen binding fragment thereof, that binds to a surface-expressed, surface-accessible or surface-localized component of a tumor cell, tumor vasculature or tumor stroma; and
(b) subsequently administering a second antibody to the animal or patient in an amount effective to inhibit metastasis from any surviving tumor cells; wherein the second antibody is at least a first VEGFR2-blocking, anti-VEGF antibody, or antigen-binding fragment thereof, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595); and further optionally wherein the antibody or fragment is operatively associated with a second anti-angiogenic agent.
In particularly preferred embodiments, the present invention provides VEGFR2-blocking, anti-VEGF antibodies and 2C3-based antibodies for use in combination with prodrugs and ADEPT. In such compositions, combination, pharmaceuticals, kits, methods and uses, the VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody or fragment thereof will be modified to provide a converting or enzymatic capacity, or operatively associated with, preferably covalently linked or conjugated to, at least a first converting agent or enzyme capable of converting at least one prodrug to the active form of the drug.
The enzymatic or enzyme-conjugated antibody or fragment will combined with an initially separate formulation of the xe2x80x9cprodrugxe2x80x9d. The prodrug will be an inactive or weakly active form of a drug that is that is converted to the active form of the drug on contact with the enzymatic capacity, converting function or enzyme associated with the VEGFR2-blocking, anti-VEGF or 2C3 antibody.
Accordingly, kits are provided that comprise, preferably in separate compositions and/or containers:
(a) a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody, or fragment thereof, that has an enzymatic function, preferably where the antibody or fragment is operatively associated with, covalently linked or conjugated to, at least a first enzyme; and
(b) a biologically effective amount of at least a first substantially inactive prodrug that is converted to a substantially active drug by the enzymatic function of, or enzyme associated with, linked to or conjugated to the VEGFR2-blocking, anti-VEGF or 2C3 antibody or fragment.
The present invention further provides advantageous methods and uses that comprise:
(a) administering to an animal or patient with a vascularized tumor a biologically effective amount of at least a first pharmaceutical composition comprising at least a first VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody, or antigen binding fragment thereof, wherein the antibody or fragment has an enzymatic function, preferably wherein the antibody or fragment is operatively associated with, covalently linked to, or conjugated to, at least a first enzyme; wherein said antibody or fragment localizes to the vasculature, intratumoral vasculature or stroma of the vascularized tumor after administration; and
(b) subsequently administering to the animal or patient, after an effective time period, a biologically effective amount of at least a second pharmaceutical composition comprising a biologically effective amount of at least one substantially inactive prodrug; wherein the prodrug is converted to a substantially active drug by the enzymatic function of, or enzyme associated with, linked to, or conjugated to the VEGFR2- blocking, anti-VEGF or 2C3 antibody or fragment localized within the vasculature, intratumoral vasculature or stroma of said vascularized tumor.
In certain other embodiments, the antibodies and immunoconjugates of the invention may be combined with one or more diagnostic agents, typically diagnostic agents for use in connection with angiogenic diseases. A range of diagnostic compositions, kits and methods are thus included within the invention.
In terms of cancer diagnosis and treatment, the diagnostic and imaging compositions, kits and methods of the present invention include in vivo and in vitro diagnostics. For example, a vascularized tumor may be imaged using a diagnostically effective amount of a tumor diagnostic component that comprises at least a first binding region that binds to an accessible component of a tumor cell, tumor vasculature or tumor stroma, operatively attached to an in vivo diagnostic imaging agent.
The tumor imaging is preferably conducted to provide an image of the stroma and/or vasculature of a vascularized tumor using a diagnostic component that comprises at least a first binding region that binds to an accessible component of tumor vasculature or tumor stroma. Any suitable binding region or antibody may be employed, such as those described above in terms of the therapeutic constructs. Certain advantages will be provided by using a detectably-labeled VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody construct, wherein the image formed will be predictive the binding sites of the therapeutic to be used.
Detectably-labeled in vivo tumor diagnostics , whether VEGFR2-blocking, anti-VEGF antibody or 2C3-based or not, may comprise an X-ray detectable compound, such as bismuth (III), gold (III), lanthanum (III) or lead (II); a radioactive ion, such as copper67, gallium67, gallium68, indium111, indium113, iodine123, iodine125, iodine131, mercury197, mercury203, rhenium186, rhenium188, rubidium97, rubidium103, technetium99m or yttrium90; a nuclear magnetic spin-resonance isotope, such as cobalt (II), copper (II), chromium (III), dysprosium (III), erbium (III), gadolinium (III), holmium (III), iron (II), iron (III), manganese (II), neodymium (III), nickel (II), samarium (III), terbium (III), vanadium (II) or ytterbium (III); or rhodamine or fluorescein.
Pre-imaging before tumor treatment may be carried out by:
(a) administering to the animal or patient a diagnostically effective amount of a pharmaceutical composition comprising a diagnostic agent operatively attached to at least a first binding region that binds to an accessible component of a tumor cell, tumor vasculature (preferably) or tumor stroma (preferably), including diagnostic agents operatively attached to VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody constructs; and
(b) subsequently detecting the detectably-labeled first binding region (or VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody) bound to the tumor cells, tumor blood vessels (preferably) or tumor stroma (preferably); thereby obtaining an image of the tumor, tumor vasculature and/or tumor stroma.
Cancer treatment may also be carried out by:
(a) forming an image of a vascularized tumor by administering to an animal or patient having a vascularized tumor a diagnostically minimal amount of at least a first detectably-labeled tumor binding agent, preferably a VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody construct, comprising a diagnostic agent operatively attached to the tumor binding agent or VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody, thereby forming a detectable image of the tumor, tumor vasculature (preferably), or tumor stroma (preferably); and
(b) subsequently administering to the same animal or patient a therapeutically optimized amount of at least a first naked VEGFR2-blocking, anti-VEGF antibody or 2C3 antibody or therapeutic agent-antibody construct using such an antibody, thereby causing an anti-tumor effect.
Imaging and treatment formulations or medicaments are thus provided, which generally comprise:
(a) a first pharmaceutical composition comprising a diagnostically effective amount of a detectably-labeled tumor binding agent, preferably a VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody construct, that comprises a detectable agent operatively attached to the tumor binding agent or VEGFR2-blocking, anti-VEGF antibody or 2C3-based antibody; and
(b) a second pharmaceutical composition comprising a therapeutically effective amount of at least one naked VEGFR2-blocking, anti-VEGF antibody or 2C3 antibody or therapeutic agent-antibody construct using such an antibody.
The invention also provides in vitro diagnostic kits comprising at least a first composition or pharmaceutical composition comprising a biologically effective amount of at least one diagnostic agent that is operatively associated with at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody 2C3 (ATCC PTA 1595), or an antigen-binding fragment thereof.
The invention still further provides combined kits in which the diagnostic agent is intended for use outside the body, preferably in connection with a test conducted on a biological sample obtained from an animal or patient. As such, the invention provides kits comprising, generally in at least two distinct containers, at least a first composition, pharmaceutical composition or medicinal cocktail comprising a biologically effective amount of at least a first VEGFR2-blocking, anti-VEGF antibody, optionally one that binds to substantially the same epitope as the monoclonal antibody2C3 (ATCC PTA 1595), or an antigen-binding fragment or immunoconjugate of such an anti-VEGF antibody; and a biologically effective amount of at least one diagnostic agent, component or system for in vitro use.
The xe2x80x9cdiagnostic agent, component or system for in vitro usexe2x80x9d will be any diagnostic agent or combination of agents that allow the diagnosis of one or more diseases that have an angiogenic component. The in vitro diagnostics thus include those suitable for use in generating diagnostic or prognostic information in relation to a disease or disorder as disclosed in any one of U.S. Pat. Nos. 5,712,291, 5,753,230, 5,972,922, 5,639,757, WO 98/45331 and WO 98/16551, each specifically incorporated herein by reference.
In terms of cancer diagnosis and treatment, the in vitro diagnostics will preferably include a diagnostic component that comprises at least a first binding region that binds to an accessible component of a tumor cell, tumor vasculature (preferably) or tumor stroma (preferably) operatively attached to a xe2x80x9cdetectable or reporter agentxe2x80x9d directly or indirectly detectable by an in vitro diagnostic test. xe2x80x9cDetectable or reporter agentsxe2x80x9d directly detectable in vitro include those such as radiolabels and reporter agents detectable by immunofluorescence.
xe2x80x9cDetectable or reporter agentsxe2x80x9d indirectly detectable in vitro include those that function in conjunction with further exogenous agent(s), such as detectable enzymes that yield a colored product on contact with a chromogenic substrate. Indirect detection in vitro also extends to detectable or reporter components or systems that comprise the first binding region that binds to an accessible component of a tumor cell, tumor vasculature (preferably) or tumor stroma (preferably) in combination with at least one detecting antibody that has immunospecificity for the first binding region. The xe2x80x9cdetecting antibodyxe2x80x9d is preferably a xe2x80x9csecondary antibodyxe2x80x9d that is attached to a direct or indirect detectable agent, such a radiolabel or enzyme. Alternatively, a xe2x80x9csecondary and tertiary antibody detection systemxe2x80x9d may be used, including a first detecting antibody that has immunospecificity for the first binding region in combination with a second detecting antibody that has immunospecificity for the first detecting antibody, the second detecting antibody being attached to a direct or indirect detectable agent.